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Cells
Discovery of Cells• Robert Hooke
• Developed crude ________________• Looked at ___________ under scope• Saw small squares, called _________• (after monk’s cells)
• Anton van Leeuwenhoek• Greatest Early _______________• Good at ____________ specimens• First saw ___________ under a single lens scope
2
Cell Theory•Living things are composed of ________________________
•Cells are the _________________ of structure and function
•Cells come from ___________________ cells
How Big is a Cell?How Big is a Cell?
_______ (diameter = 0.000008in)
20,000 bacterial cells = _______
3
Why Are Cells So Small?High __________________________ ratio!!
Greater the SURFACE, more stuff gets ___________ of cell
Greater the VOLUME, less stuff gets in or out; cell _________or is _______________
Characteristics of CellsSizeSize varies-most are ______Bacteria cell à _________Nerve cellsà ___________
Spinal Neuron-Over 3 feet long
Sperm Cell- 25 Micrometers
4
2 Major Types of Cells•Prokaryotic Cell à ___________ (usually ____________) with a small, _______________ of DNA. Usually ________________
•Eukaryotic Cell à __________cells with ______________functions and structures. Always _______________________
Prokaryotic Cell Eukaryotic Cell
Eukaryotic Cells•In this unit we will study __________________cells
•Microbiology = ___________________ cells
•__________________________________ are eukaryotic cells•Multi-cellular organisms are usually made from many different types of cells (______________________)
5
3 Major Parts of the Eukaryotic Cell
_____ major parts of cells:• Plasma Membrane
• Controls passage of materials ________________of cell
• Nuclear Region• Controls the _______________________• Contains __________________ material
• Cytoplasm• Contains __________________________
Internal Organization of Eukaryotic Cells
Each cell contains miniature organs called _________
Each organelle performs ___________________ for the cell
6
Cytoplasm
• All of the area ______________________________ and the nucleus
• Contains all of the _______________ within the cell.
Ribosomes
• Make ____________ from _______________ (AA);
• Found ____________ or in cytosol.
7
Rough Endoplasmic Reticulum(ER)
• Makes ___________ and _____________ them to other parts of the cells via ____________ (little packages).
Smooth Endoplasmic Reticulum
• _____________ proteins
8
Golgi Apparatus
• Found ______________.• Takes proteins from ER
and ______________ to make them work; then sends them on their way (_____________ of the cell).
9
Mitochondrion
• _______________ of the cell.
• Takes in food and ____________________, which is broken down for energy
• Some cells have ____________________mitochondrion than others.
Cristae
• Folds in the inner _____________________ of the mitochondria to increase the _______________area
10
Nucleus
• Controls and coordinates cell activities. Contains ___________________
• DNA converted to ____________ and stored in ___________. RNA sent out to cell as a _________________.
Nucleus
• Surrounded by ____________________.
• Nuclear pores allow ____________________ nucleus.
11
Nucleus
Image Source: Miss Reed’s PowerPoint on Cells.
Nuclear Membrane
• Surrounds _______________material
12
Cytoskeleton
• Scaffolding that gives cell shape.• Microfilaments -used
for _______________• Microtubules -thicker,
__________________
Cilia and Flagella
• Help some cells _________________
• Some found in the lining of _______________ tract.
Flagellum
Cilia
13
Lysosomes
• Contain _______________ enzymes
• Breaks down ___________
• Can ___________________ cell.
Centrioles
• Set of _______________ that move _______________during mitosis
14
Plasma Membrane
• Selective _____________________________ and communication
Plant Cell Organelles
•Cell Wall à ______________________ and gives cell shape
•Vacuoles à _____________________, water; gives plant cells shape
•Chloroplasts à Found only in plant cells, Used to _____________________________
15
Plant Cell Organelles
Cell Transport
16
Structure of Plasma Membrane
• Selectively Permeable à allows some molecules _______; keeps others ___________
• Phospholipid Bilayerà ______heads on ______________________ of cell; _______ tails on inside of membrane
• Polar = Hydrophilic = _____________• Nonpolar = hydrophobic = water
_____________
Why is there this arrangement of lipids?Cytoplasm and outside of cell is ___________
Molecules on the Plasma Membrane
n Carbohydrates à Act as receptors; molecules attach to cell; tell it what to do
n Cholesterol à Gives membrane shape; rigidityn Proteinsà Anchor cytoskeleton; channel
nutrients and other substances into the cell
Protein Receptors coming out of plasma membrane
17
Crossing the Plasma Membrane
How do some substances pass through the membrane while others stay out?
Materials moves across the membrane in twoways1. _________________________2. _________________________
Passive Transport
n Diffusion à movement of molecules from _______________________to low concentration
n _______________________ molecules, and water pass through the membrane by diffusion
Equilibrium àOccurs when equal amounts of a substance are on either side of the cell
18
Osmosis
• Osmosis à diffusion of ______________
• Isotonic Solution àCells are at _____________; __________________ of water
• Hypertonic solution à Cell is in a solution that has _______________ or other ions in it; water rushes out of the cell and the ______________
• Hypotonic solution àCell is in a solution that has _____________________ or other ions in it; water rushes into the cell and the __________________
Tonicity in Red Blood Cells
19
Active Transport
Active Transport à __________________ to transport large molecules into the cell ______________their concentration gradients
1. Cell Membrane Pumps à carrier proteins pump ions _______________________________________
2. Endocytosis à _______________ of _________________particles or liquids by plasma membrane
Cells take in __________ by endocytosis from bloodPinocytosis à Endocytosis of _______________3. Exocytosis à vesicle contents __________ by cell_________________ are transported by exocytosis
Exocytosis Animation
20
Endocytosis Animation
From Cell to OrganismTissueà Groups of __________ performing the same task
Exp. Nerve Tissue à transmits ________________________Epithelial Tissue à ___________________ outer layer
Organ à Groups of ______________ performing the same taskExp. Heart à Circulate _______________ through body
System à Group of _______________ working togetherExp. _________________ System
_________________ system
Organism à Groups of __________________ working together
21
Compound Light Microscope
n Parts to Know…A. BaseB. PillarC. ArmD. StageE. SlideF. CoverslipG. Stage clipsH. Light source/
Mirror
I. Low power objectiveJ. High power objectiveK. Body TubeL. Ocular/EyepieceM. Coarse adjustment
knobN. Fine adjustment knobO. NosepieceP. Diaphragm
Cell Organelles Chromebook Assignment Name______________ Directions:
1. Go to YouTube 2. Type in “A Tour of the Cell”. Look for the video posted
that is 14:17 minutes long 3. Follow along the video and answer the following questions
Questions Along the Way
1. Why are cells so small?
2. Cells were invisible until the invention of the ______________________?
3. What is the difference between a transmission electron microscope and a scanning electron microscope?
4. Which types of organisms are prokaryotic?
5. The nucleolus makes _______________.
6. What material is found inside the nucleus?
7. What 2 types of RNA are found on ribosomes?
8. The “container” of the cell is the ___________________?
9. The rough ER is attached to the _____________________ 10. This part of the cell ships and packages proteins.
11. The thick filaments in the cytoskeleton are called_________________. The thin filaments of the cytoskeleton are called _______________________
12. The smooth ER produces ________________ and helps detoxify cells.
13. Which organelle generates ATP? _______________
14. This organelle could kill the cell: ________________
15. These types of cells don’t have centrioles: __________________________
Name ______________________________ Class___________________Date__________________
Skills Worksheet
Directed Reading
Section: Introduction to Cells Read each question, and write your answer in the space provided.
1. How and when did scientists discover cells?
_______________________________________________________________
_______________________________________________________________ 2. What is the cell theory? Who formulated it and when?
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________ 3. How do cells vary in shape?
_______________________________________________________________
_______________________________________________________________ 4. Why is it an advantage for cells to be small?
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________
In the space provided, write the letter of the description that best matches each term.
_____ 5. cell membrane a. cell fluid and structures b. cell structure where proteins are made c. cell structures that carry out specific
functions d. genetic information e. membrane-bound structure that houses a
cell’s DNA f. the outer boundary of a cell
_____ 6. cytoplasm
_____ 7. DNA
_____ 8. ribosome
_____ 9. organelles
_____ 10. nucleus
Original content Copyright © by Holt, Rinehart and Winston. Additions and changes to the original content are the responsibility of the instructor.
Holt Biology 1 Cell Structure
Name ______________________________ Class___________________Date__________________ Directed Reading continued
Read each question, and write your answer in the space provided.
11. What are prokaryotes, what are they like, and when did they arise?
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________ 12. How do eukaryotes differ from prokaryotes? When did eukaryotes arise?
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________
Write p if the cell feature is found in prokaryotes. Write e if the cell feature is found in eukaryotes. Write b if the cell feature is found in both prokaryotes and eukaryotes.
_____ 13. cell membrane
_____ 14. cytoplasm
_____ 15. capsule
_____ 16. DNA
_____ 17. ribosomes
_____ 18. organelles
_____ 19. nucleus
Original content Copyright © by Holt, Rinehart and Winston. Additions and changes to the original content are the responsibility of the instructor.
Holt Biology 2 Cell Structure
Name ______________________________ Class___________________Date__________________
Skills Worksheet
Active Reading
Section: Introduction to Cells Read the passage below. Then answer the questions that follow.
The first cells to appear on Earth were prokaryotic cells. A prokaryote is an organism made of a single prokaryotic cell. The earliest prokaryotes may have arisen more than 2.5 billion years ago. Bacteria are prokaryotes. They are very small cells with a simple structure. Prokaryotes do not have a nucleus. This means that their DNA is not enclosed in a membrane inside the cell. Instead, prokaryotes have a single loop of DNA that floats in the cell’s cytoplasm. Protein-making bodies called ribosomes also form part of the cytoplasm. Like all cells, prokaryotes have a cell membrane. All prokaryotes also have a cell wall surrounding the cell membrane. The cell wall helps provide support and protection for the cell. Some prokaryotes are enclosed by an additional layer. This layer is called the capsule. The capsule has a sticky surface area, so it allows prokaryotes to cling to surfaces, such as your skin and your teeth.
Eukaryotic cells are more complex than prokaryotic cells. They all have a cell membrane, ribosomes, and DNA as prokaryotic cells do. However, the DNA of eukaryotic cells does not float freely in the cytoplasm. Instead, it is found in the nucleus, an internal compartment bound by a cell membrane. The nucleus is one kind of organelle found in eukaryotic cells. Organelles are structures that perform specific functions. Most organelles are surrounded by a membrane. Some organelles have membranes that form channels which help transport substances from one part of the cell to another part of the cell.
Eukaryotes are organisms made of one or more eukaryotic cells. The earliest eukaryotes, like the first prokaryotes, were single-celled organisms. They arose about 1 billion years later than the earliest prokaryotes. Later, multicellular eukaryotes arose. Every type of multicellular organism that exists is made up of eukaryotic cells.
SKILL: READING EFFECTIVELY Read each question, and write your answer in the space provided. 1. What is a prokaryote, and when did prokaryotes arise?
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________
Original content Copyright © by Holt, Rinehart and Winston. Additions and changes to the original content are the responsibility of the instructor.
Holt Biology 7 Cell Structure
Name ______________________________ Class___________________Date__________________ Active Reading continued
2. Describe three main features inside a prokaryotic cell.
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________ 3. Describe the structures that form the outside of a prokaryotic cell. Tell whether
each structure is common to all prokaryotes.
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________ 4. What is a eukaryote, and when did eukaryotes first arise?
_______________________________________________________________
_______________________________________________________________
SKILL: ORGANIZING IFill in the Venn di
NFORMATION agram to
In the space provided, write the letter of the phrase that best answers the
From which type of cells did multicellular organisms arise?
with a capsule
and eukaryotic cells
compare and contrast the structure of prokaryotic and eukaryotic cells.
question.
_____ 8. a. prokaryotic cells b. prokaryotic cells c. eukaryotic cells d. both prokaryotic
Original content Copyright © by Holt, Rinehart and Winston. Additions and changes to the original content are the responsibility of the instructor.
Holt Biology 9 Cell Structure
YoutubeCellOrganelles Name_________________________
Thefollowingiactivitycomparesandcontrastssomeofthemajor
organellesfoundineukaryoticcells
Directions:1. UsingyourChromebook,goto“Google”2. Clickon“Video”3. Inthesearchbar,typein“Cellularorganelles”4. ThefirstvideoshownshouldbefromBozemanScience.Clickonthatlinkandanswerthefollowingquestions:
Questionsalongtheway:
1. Whatisthecontrolcenterofthecell?______________________
2. WhatorganellesmaketheroughER“rough”?
3. Plantcellsstorewaterin_________________
4. Organellesarefoundin_______________________________cells
5. Howmanysubunitsareinaribosome?____________
6. WhodiscoveredtheGolgiApparatus?_______________________
7. Thisorganellecanactuallykillthecell:_____________________
8. Whyis“folding”importantinBiology?
9. Thethylakoidispartofwhatorganelle?_____________________________
10.Whatisthestroma?_______________________________________________
_____________________________________________________
HudsonAlphaCell Name_______________________________Overview:Thisexerciseisdesignedtoprovidestudentsavisualcontextforthedifferentorganellesthatcanbefoundinplant,animal,andbacterialcells.Procedure:YoumustfirstdownloadHudsonAlphaCellfromiTunes.It‘sfree.JustgototheappstoreonyourChromebookandsearch“Hudsonalphacell”.Onceyoufindityoucanopenitupandbegin!Toanswereachquestionyouwilllikelyhavetoclickonthe“basic”,“intermediate”,and“advanced”buttonsforeachorganelle.Goodluck!BacteriaCellNucleoidRegion1. Thenucleoidregionofthebacterialcellcontains__________________
2. Thenucleoidregionisnotenclosedbya_______________________________
3. Whatistheshapeofthebacterialgenome(DNA)?____________________________
CellMembrane&Cytoplasm1. Thisisthefunctionofthecellmembrane:_____________________________________________________________
______________________________________________________________________________2. Thisisthefluidthatfillsthebacterium___________________________________
3. Theseproteinmolecules,foundinthecytoplasm,carryoutreactionsforthebacterium____________________________________________
4. Thecellmembraneismadefromthesetypesoflipids____________________________________
Flagella1. Whatisthefunctionofthebacterialflagella?_________________________________________________________________________________________________2. Howfastcanaflagellummoveabacterialcell?__________________
Plasmids1. Whatareplasmids?_________________________________________________________________________________________________2. Whatare2possiblefunctionsofplasmids?________________________________________________________________________________________________
3. Howareplasmidsusedinbiotechnology?__________________________________________________________________________________________
PlantCellCellWall1. Whatisacellwall?________________________________________________
2. Whatisthecellwallmadefrom?_________________________________
3. Whyarecellwallssostrong?________________________________________________________________________________________________________EndoplasmicReticulum1. Whatisthefunctionoftheendoplasmicreticulum?_______________________________________________________________________________
2. WhatorganelleistheERconnectedto?___________________________3. WhatotherorganellesareattachedtothesurfaceoftheER?_____________________________
4. TheRoughERmakes____________________whiletheSmoothERmakes___________________________
Nucleus1. Thenucleusholds_______________forplantandanimalcells
2. Howmanymembranessurroundthenucleus?__________
3. Whatorganelledoesthenucleolussynthesize(make)________________________
Vacuole1.Whatisthefunctionofavacuoleinaplantcell?___________________________________________________________2.Underoptimalconditionsthevacuolestoreswhat?______________Chloroplast1. Chloroplastsconvertenergyfromthe__________into______________usingaprocesscalled_______________________
AnimalCellGolgiBody1.Thegolgibodymodifiesandpackages__________________2. Thegolgibodyisastackof______________________3. MoleculesmadebytheERarriveatthegolgibodyinapackagecalleda_________________________
Mitochondrion1. Themitochondriaproduces_______________forthecell.
2. Themitochondriametabolizes(orbreaksdown)_____________into_____________________
3. Unlikeotherorganelles,themitochondriahasitsown______________
Nucleolus1. Thenucleoluscontainsadensebundleof_________________and__________.
CellMembrane1. Thecellmembraneismadefrom_______________________andproteins.
2.Whatarethemaincomponentsofaphospholipid?____________________________________________________________2. List4functionsofthecellmembrane:
Centrioles
1. Centriolesareonlyfoundin______________cells
2. Theyhelp_______________________________
3. Centrioleshelptoform_____________________________________________
4. Centriolesaremadefrom__________________________________
Name ______________________________ Class___________________Date__________________
Skills Worksheet
Directed Reading
Section: Inside the Eukaryotic Cell Read each question, and write your answer in the space provided.
1. What is the cytoskeleton, and what is its function?
_______________________________________________________________
_______________________________________________________________ 2. What are three types of cytoskeleton fibers, and what does each do?
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________ 3. What is the main function of the nucleus, and why is this essential for the
health of the cell?
_______________________________________________________________
_______________________________________________________________ 4. What is the nucleolus, where is it, and what is its function?
_______________________________________________________________
_______________________________________________________________ 5. What are the two types of ribosomes, and what does each do?
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________ 6. Describe the endoplasmic reticulum, and tell what the two different kinds of
endoplasmic reticulum do.
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________
Original content Copyright © by Holt, Rinehart and Winston. Additions and changes to the original content are the responsibility of the instructor.
Holt Biology 3 Cell Structure
Name ______________________________ Class___________________Date__________________
Directed Reading continued
7. How does the Golgi apparatus continue the function of the rough ER?
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________ 8. What are two functions of lysosomes?
_______________________________________________________________
_______________________________________________________________ 9. What do contractile vacuoles in plants do?
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________ 10. What do contractile vacuoles in protists do?
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________ 11. What is ATP?
_______________________________________________________________
_______________________________________________________________ 12. What are chloroplasts, how are they structured, and in what kinds of cells are
they found?
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________ 13. What function do mitochondria perform? Why do some cells contain many
mitochondria?
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________
Original content Copyright © by Holt, Rinehart and Winston. Additions and changes to the original content are the responsibility of the instructor.
Holt Biology 4 Cell Structure
AnimalCellStructures&Organelles-MicroviewerLabName______________________Purpose:ToobservecellstructuresnotvisibleusinglightmicroscopesMaterials:Microviewer;slidesandbookletProcedure:Usethemicroviewertoobservethestructuresandorganellesoftheanimalcell.Drawwhatyousee,andlabeleachstructureororganelle.Refertothereadingthatgoesalongwitheachslidetohelpinlabelingyourdiagrams.Slide1:Thisslideshowsmanycellsfromahumanoilgland.Drawonecell,andlabelthecellmembrane,nucleus,andcytoplasm.Slide2:Drawandlabeltheendoplasmicreticulum,ribosomes,mitochondria,nucleus,andnucleolus.Slide4:Drawandlabelthegolgiapparatus(Golgibody)andvacuole.Slide7:Drawandlabelthechromosomes
AnalysisQuestions.Refertoyournotesoncellstructuresandthereadinginthebooklettoanswerthefollowingquestions.
1. NoticethewaytheERwindsthroughoutthecell.HowdoesthisarrangementhelptheERtoperformitsjoboftransportingproteinsthroughoutthecell?
2. Cellsthatneedaconstantsupplyofenergyhavelotsofmitochondria.Whereinyourbodywouldonefindcellswithlotsofmitochondria?
3. Whatimportantinformationisfoundonchromatin?
4. Onceproteinsaremadeintheribosome,theymusttraveltowhatstructuretobeprocessedbeforeleavingthecell?
5. Ifyouwerelookingataplantcell,howwouldyouexpectthevacuoletolookincomparisontoananimalcell?
6. Whywouldyouexpectyourmusclecellstohavelotsofribosomes?
7. Whatstructureiscontrollingaloftheactivitieswithinthecell?
8. WhatisthekeystructuraldifferencebetweentheroughERandsmoothER?
9. Whenevermaterialsneedtoenterorleaveacell,whatstructuresmusttheypassthroughinananimalcell?Plantcell?
10. Whatstructurewouldyouexpecttoseeattachedtothevacuole,responsibleforthedigestionofglucose?
Name ______________________________ Class___________________Date__________________
Skills Worksheet
Active Reading
Section: Inside the Eukaryotic Cell Read the passage below. Then answer the questions that follow.
Vesicles that contain newly made proteins move from the endoplasmic reticulum (ER), through the cytoplasm, to an organelle called the Golgi apparatus. The Golgi apparatus is a set of flattened, membrane-bound sacs that serves as the packaging and distribution center of the cell. Protein-containing vesicles from the ER enter one side of the Golgi apparatus. Enzymes inside the Golgi apparatus modify those proteins. The modified proteins are then enclosed in new vesicles that bud from the surface of the other side of the Golgi apparatus. Many of these vesicles move to the cell membrane and release their contents outside the cell. The ER and the Golgi apparatus work together in the production, packaging, and distribution of proteins.
SKILL: READING EFFECTIVELY
Read each question, and write your answer in the space provided.
1. Describe the path that vesicles containing newly made proteins take in the cell.
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________ 2. What is the Golgi apparatus?
_______________________________________________________________
_______________________________________________________________ 3. How do proteins arrive at the Golgi apparatus, and what happens to them
there?
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________
Original content Copyright © by Holt, Rinehart and Winston. Additions and changes to the original content are the responsibility of the instructor.
Holt Biology 9 Cell Structure
Name ______________________________ Class___________________Date__________________ Active Reading continued
4. What happens to many of the protein-containing vesicles when they are released from the Golgi apparatus?
_______________________________________________________________
_______________________________________________________________
In the space provided, write the letter of the term or phrase that best answers each question.
_____ 5. Where do proteins that enter the Golgi apparatus come from? a. cell nucleus b. endoplasmic reticulum c. outside the cell d. digested materials inside the cell
_____ 6. What role do vesicles play in processing the proteins in the Golgi apparatus? a. They create the proteins. b. They modify the proteins. c. They store the proteins. d. They transport the proteins.
Original content Copyright © by Holt, Rinehart and Winston. Additions and changes to the original content are the responsibility of the instructor.
Holt Biology 10 Cell Structure
Cells Laboratory Purpose:
• To identify living cells in an aquatic environment • To describe different types of eukaryotic cells • To compare plant and animal cells
Materials: microscope slide cover slip prepared slides elodea living protists Part I. Elodea Cells
1. Obtain a microscope and plug it in 2. Prepare a wet mount of an elodea leaf 3. On your data sheet, draw what you see. Label cell wall,
membrane, and chloroplasts 4. Throw out the leaf, rinse and dry your cover slip and slide
Part II. Prepared Cells
1. Obtain a microscope and plug it in 2. Obtain a prepared cell slide from the front desk. **Note that
many of these are bacterial and fungal cells! 3. On your data sheet, draw what you see and identify the type of
cell for your observation 4. Place prepared slide back on the front desk
Part III. Living Cells
1. Obtain a microscope and plug it in 2. Prepare a wet mount using “live” water from the back lab table 3. On your data sheet, draw what you see. Try to find at least 3
living organisms! 4. Rinse and dry your cover slip and slide
Data Elodea Cells Draw what you observed under 40x and 100x. Label cell wall, membrane, and chloroplasts 40x 100x Prepared Cells Type of Cells _____________________________________ Draw what you observed under 40x and 100x. 40x 100x Living Cells Draw 2 microscopic organisms that you observed under the microscope Organism #1 Organism #2
A Day In the Life of a Cell
When looking at a day in the life of a cell, it’s important to note that cells are very similar entire organisms. They need to take in energy, use it to make stuff (like proteins), and release waste that will not be used. So, let’s take a look at what happens to the cells in your body after you eat food. As the food passes through your digestive system, it is broken down to a simple sugar, glucose. Glucose is then passed through the blood to the cells all over your body. Glucose first enters through the plasma membrane of the cell. In the cytoplasm, glucose is broken down (sometimes by lysosomes) to smaller molecules. These smaller molecules then enter the mitochondria where they are converted to ATP. ATP stands for Adenosine Triphosphate, but what you really need to know about ATP is that it is used as an energy source for the cell. When ATP is broken down, energy is released and used by the cell. What does the cell use energy for? Well, most importantly, the cell is all about making proteins, and energy is needed to make proteins. Remember that proteins are the substances that give cells (and organisms) their physical structure. Some important proteins are 1. Hemoglobin- blood protein that carries oxygen 2. Keratin- protein found in fingernails and hair 3. Collagen- protein that makes up connective tissue, muscles and bones
How are these proteins made? Well, you might remember from earlier in the year that different proteins are made from DNA. DNA gets transcribed to mRNA, which then leaves the nucleus through the nuclear pores. The mRNA then travels to the ribosomes (found in the cytosol or on the Rough ER), where it is translated into proteins. These proteins, after they are made, must get modified so they can work. These proteins then travel (through the Rough ER or the Smooth ER) to the Golgi Apparatus. The Golgi Apparatus adds chemicals so that the proteins can work. The proteins are then shipped within the cell, or out of the cell, by travelling through the Rough ER or Smooth ER. The protein then leaves the cell and becomes part of your body.
Osmosis Tutorial Name _____________________ Directions: Go to youtube and search for “osmosis”. The 3rd or 4th video down is a detailed explanation of Osmosis from the “Khan Academy”. Play the video, with audio, and answer the following questions
1. The solution there is “more of” is called the _____________________
2. The solution there is “less of” is called the _____________________
3. What is diffusion? ____________________________________________ _________________________________________________
4. What is the chemical definition of “concentration”? ___________________ ____________________________________
5. Which way do sugar particles move in the two containers? Right to left or left to right?
6. In the two connected containers, which had a higher concentration of solute? Right or Left?
7. Solutions with high concentrations are called ___________________ solutions
8. Solutions with low concentrations are called ___________________ solutions
9. What is a semi-permeable membrane? ________________________ ______________________________________ 10. Can sugar pass through the semi-permeable membrane? Why or why
not? _____________________________________________________
11. Water tends to move from ________________ concentration to ___________________ concentration.
12. The diffusion of water is called _____________________________
13. Is water usually the solute or the solvent in a solution? Why _______________________________________________________
______________________________________________________
Osmosis Through Living Cells Name _____________________ Materials Microscope Microscope Slides Salt Water Distilled Water Elodea Cover slips Pipette Cells in Equilibrium
1. Make a wet mount of an elodea leaf using water from the tank that the leaves are in
2. Observe the Cells at 40X and 100X 3. Draw what you see below
Cells in Salt Water
1. Make a wet mount of an elodea leaf using salt water 2. Observe the Cells at 40X and 100X 3. Draw what you see below
Cells in Distilled Water
1. Make a wet mount of an elodea leaf using salt water 2. Observe the Cells at 40X and 100X 3. Draw what you see below
Analysis Questions
1. The cells in the tank water are in equilibrium. What does that mean?
2. When cells are at equilibrium, is there any net movement of water into or out of the cells?
3. When elodea cells were placed in salt water, did water enter or leave the
cell? What type of solution were these cells placed in?
4. When elodea cells were placed in distilled water, did water enter or leave the cell? What type of solution were these cells placed in?
5. What happens to the osmotic pressure of a cell when in is placed in salt
water?
6. What happens to the osmotic pressure of a cell when in is placed in distilled water?
Cell Equilibrium Visual Concepts Name _________________________ Directions: Go to the following web page from this textbook: http://my.hrw.com/ username: allb7 password:lions 1. Log on to the Holt McDougal Website 2. Proceed to the Interactive Online Edition of your Biology textbook 3. Select “Chapter 8: Cells and Their Environment” from the chapter box on the top left of your
screen. 4. Click on the “eActivities” tab 5. Proceed to the left side of the page and find Visual Concepts. Look down until you find Cell
Membrane 6. Proceed at your own pace through the Visual Concepts. Answer the questions as you move through
the activity. Make sure you have the volume turned up so that you can hear the narration! Phospholipid 1. This structure is the central component of the cell membrane___________________________
2. What is the polar head of a cell membrane made from? _______________________________ 3. How many nonpolar tails are there in a phospholipid? _____________________________ Lipid Bilayer 4. A cell membrane is made from _______ layers of phospholipids. 5. Are the lipid tails facing inward or outward in the lipid bilayer? ________________________ 6. Phospholipid tails repel ______________________ Parts of the Cell Membrane 7. Compare the location of steroids and carbohydrates on the cell
membrane?_______________________________________________________
8. What is the structural difference between a transport and peripheral protein? ___________________________
Cell Equilibrium Visual Concepts Name _________________________ Directions: Go to the following web page from this textbook: http://my.hrw.com/ username: allb7 password:lions 1. Log on to the Holt McDougal Website 2. Proceed to the Interactive Online Edition of your Biology textbook 3. Select “Chapter 8: Cells and Their Environment” from the chapter box on the top left of your
screen. 4. Click on the “eActivities” tab 5. Proceed to the left side of the page and find Visual Concepts. Look down until you find Cell
Transport 6. Proceed at your own pace through the Visual Concepts. Answer the questions as you move through
the activity. Make sure you have the volume turned up so that you can hear the narration! Comparing Hypertonic, Isotonic, and Hypotonic Solutions 1. The movement of water across a cell membrane is called __________________________
2. The net direction of osmosis is dependent on ______________________________________ _____________________________________________ 3. What are solutes? ____________________________________ 4. What is the difference between an organic and inorganic compound? It is NOT found in this activity. Look it up and answer in your own words!______________________________________________ ________________________________________________________________________________ 5. Which way does water move in a hypertonic solution? ___________________________________ 7. Is there more solute inside or outside of the cell in a hypertonic solution? _____________________
8. Which way does water move in an isotonic solution? ___________________________________
9. Is there a net movement of water in an isotonic solution? _____________________________
10. What may be the harmful results of a cell in a hypotonic solution? ______________________
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What is Active Transport? Active transport involves the use of proteins that don't just passively
diffuse across the cell membrane, but require the use of cellular energy (usually ATP) to actively pump substances into or out of the cell. An example of this type of cellular process is the action of a sodium-potassium pump found in the cell membrane of neurons (nerve cells). This protein pumps sodium ions from the inside to the outside of the neuron, and pumps potassium ions in the opposite direction. This is an interesting task for the cell because our cells already have a high concentration of sodium outside of them. Additionally, our cells have a high concentration of potassium inside the cell membrane. How does the cell get sodium into it when it already has a concentration of it outside? How does it get potassium into the cell when the interior is already high in potassium? Diffusion won’t work. The cell must use ATP for this process. As the sodium fits onto a site on the protein, a phosphate is transferred to the protein providing energy to kick the sodium ion to the outside and the potassium ion to the inside. This process sets up a high concentration of sodium ions outside the cell and a high concentration of potassium ions inside the cell. This concentration difference across the membrane is important for the generation of the nerve impulses by which neurons transmit information from on end of the neuron to the other.
Active transport is also used to:
1. Generate charge gradients. For example in the mitochondrion, hydrogen ion pumps pump hydrogen ions into the inter-membrane space of the organelle as part of making ATP.
2. Concentrate ions, minerals and nutrients inside the cell that are in low concentration outside.
3. Keep unwanted ions or other molecules out of the cell that are able to diffuse through the cell membrane.
In all these cases the key is that active transport uses energy to send substances against the direction they would travel by simple diffusion: that is from a region of low concentration to a region of high concentration.
Name ______________________________ Class___________________Date__________________
Skills Worksheet
Directed Reading
Section: From Cell to Organism Read each question, and write your answer in the space provided. 1. What are four ways that prokaryotes differ from eukaryotes?
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_______________________________________________________________ 2. What are some ways that prokaryotes can vary?
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_______________________________________________________________ 3. What are two different structures some prokaryotes have? Describe each, and
tell its function.
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_______________________________________________________________ 4. How do plant cells differ from animal cells?
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5. Define tissue, and give an example of a plant tissue and an animal tissue.
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Original content Copyright © by Holt, Rinehart and Winston. Additions and changes to the original content are the responsibility of the instructor.
Holt Biology 5 Cell Structure
Name ______________________________ Class___________________Date__________________ Directed Reading continued
6. Define organ, and give an example of an organ in plants and an organ in animals.
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_______________________________________________________________ 7. Distinguish between organs and organ systems. Give an example of an organ
system in plants and an organ system in animals.
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_______________________________________________________________ 8. Define multicellular organism.
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_______________________________________________________________ 9. What is a colonial organism? Give an example.
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_______________________________________________________________ 10. What makes multicellular organisms very different from colonial organisms?
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Original content Copyright © by Holt, Rinehart and Winston. Additions and changes to the original content are the responsibility of the instructor.
Holt Biology 6 Cell Structure
Guidelines for Cells Test Students should be able to:
• Identify cellular structures and their function, including ribosomes, rough ER, smooth ER, golgi apparatus, mitochondrion, cristae, nucleus, nuclear membrane, and nuclear pores, plasma membrane, cell wall, chloroplasts, vesicles, centrioles, vacuoles, lysosomes, cytoskeleton • Be able to locate the above organelles in a plant and animal cell
• Differentiate between plant and animal cell organelles
• Describe the early microscopists and their contribution toward cell study
• Identify the 3 major regions of the cell
• Describe the size of cells and the reason for their size
• Locate and define the different parts of the microscope
• Describe the differences between prokaryotes and eukaryotes
• Anything from the microscope labs, and Cells Ipad assignments are fair game!
• Differentiate between polar and nonpolar molecules
• Describe the plasma membrane, its structure, and be able to explain how its structure affects its function
• Describe the roles of carbohydrates, cholesterol, and proteins on the plasma membrane
• Describe how small molecules and large molecules are transported through the plasma membrane
• Define hypertonic, hypotonic, and isotonic solutions. Be able to describe how these solutions affect cell size and possible roles of these solutions in the body
• Describe how large molecules are taken into the cell. Be able to describe the process of endocytosis, exocytosis, pinocytosis, and active transport. Know which molecules are transported in the body using these processes