Cells

Cell Structure and FunctionPhotosynthesis

Cellular RespirationCell Growth and Division

Cell Structure and Function

(Chapter 7)

Life is Cellular How did the Cell Theory develop?

Cell Theory Guided Reading activity Know the contributions of the following

scientists: Robert Hooke (1665) Anton van Leeuwenhoek (1674) Matthias Schleiden (1838) Theodor Schwann (1839) Rudolph Virchow (1855) Janet Plowe (1931) Lynn Margulis (1970)

Prokaryotes vs. Eukaryotes Prokaryotes = Eukaryotes=

Use my website to determine the major differences between eukaryotes and prokaryotes.

Cell Structures Use the webquest on animal and plant cell

organelles and their functions as notes for this section.

Go to my website, click on links, then click on “cells alive!”

Or go to http://www.cellsalive.com for more information!

The Compound Microscope Review the

microscope lab activity as notes for this section! Know the parts of the

microscope and be able to accurately label a microscope diagram!

Know how to make a wet mount slide!

Cellular Diversity

Protists: Webquest on

“What are Protists?”

Protista lab activity

Animal and Plant Cells: Observing Animal

and Plant Cells lab activity

Protist Lab Video Clips Paramecium:

http://www.youtube.com/watch?v=l9ymaSzcsdY&NR=1&feature=fvwp

Euglena: http://www.youtube.com/watch?v=7DALQ-XLJ4

Q&feature=related Amoeba:

http://www.youtube.com/watch?v=I3Jo7moaLdI&feature=related

Levels of Organization in Multicellular Organisms

Use the Levels of Organization webquest as notes for this section.

Structure and Function

Choose a cell type and research how it’s structure helps it

function.

20 minute research activity:

Cells performing the same function often are similar in shape

Question: “How does the cell shape affect it’s function/allow it to function?”

Choose from one of these cell types: Neuron Red Blood Cell Cheek Epithelial Cell

Product Ideas: PowerPoint, Poster, graphic organizer, song,

interpretive dance, model, acrostic poem, concept map

Neuron

Cheek Epithelial Cell

Red Blood Cell

Neuron Notes…

Cheek Epithelial Cell Notes…

Red Blood Cell Notes…

Homeostasis in the Human Body Use the Homeostasis in the Human Body

Webquest as notes for this section.

The Cell Membrane

Structure and Function“Fluid Mosaic Model”

The Cell Membrane Regulates what enters and leaves Provides protection and support Made up of:

Phospholipids (“lipid bilayer”) Integral and Peripheral Proteins Carbohydrate chains (glycoproteins) Cholesterol

Cell membrane structure

Where are they found? Found in:

Nucleus Cell membrane Golgi apparatus endoplasmic reticulum lysosomes mitochondria (basically any

membrane bound organelle!)

Structure Lipid bilayer is made

of the following: 2 types of proteins:

Integral proteins Peripheral proteins

3 types of lipids: Membrane

Phospholipids Membrane glycolipids Cholesterol

Integral proteins Transmembrane

proteins (or integral proteins) Amphipathic =

hydrophobic and hydrophilic regions

Peripheral proteins Peripheral proteins

linked at the cytoplasmic surface (by attachment to a fatty acid chain)

linked at the external cell surface (attached by an oligosaccharide)

may be bound to other membrane proteins

Membrane Phospholipids These have a polar

head group and two hydrocarbon tails

It is connected by glycerol to two fatty acid tails

One of the tails is a straight chain fatty acid (saturated). The other has a kink in the tail (unsaturated).

Membrane glycolipids Glycolipids are also a

constituent of membranes.

These components of the membrane may be protective, insulators, and sites of receptor binding.

Cholesterol The amount of

cholesterol may vary with the type of membrane.

Plasma membranes have nearly one cholesterol per phospholipid molecule.

Other membranes (like those around bacteria) have no cholesterol

Cholesterol (continued) Function:

This makes the lipid bilayer less deformable Without cholesterol (such as in a bacterium) a

cell would need a cell wall. Also keeps the cell membrane from becoming

too stiff.

Fluid Mosaic Model Based on what you know about the

structure and function of the cell membrane what does the fluid mosaic model mean?

Diffusion, Osmosis, and Active Transport Molecular Workbench Activity Complete this online and use your analysis

packets as additional notes. We will be completing this in class!

Movement Through the Membrane

NO ENERGY (ATP) REQUIRED

ENERGY (ATP) REQUIRED

[high] [low]

[low] [high]

Materials can move through the membrane by: Diffusion

Osmosis Facilitated Diffusion Active Transport

Protein Pumps Endocytosis Exocytosis

Diffusion Requires no energy (ATP) Moves from an area of High concentration

low concentration until dynamic equilibrium is reached.

Dynamic equilibrium activity http://www.stolaf.edu/people/giannini/flash

animat/transport/diffusion.swf

Osmosis A type of diffusion (no energy needed) Allows water molecules to pass easily

through the selectively permeable membrane.

Solution = solute + solvent Solute = sugar (or another dissolved

substance)…CANNOT go through the membrane

Solvent = water…CAN go through the membrane

Osmosis ONLY water moves The solute stays put on one side or the

other Water moves back and forth according to

the concentration of water on each side of the membrane

http://www.stolaf.edu/people/giannini/flashanimat/transport/osmosis.swf

Osmotic Pressure Isotonic solutions

The 2 solutions have equal concentrations of solute and solvent.

Hypotonic solutions One solution has less solute and more water

compared to the other solution. Hypertonic solutions

One solution has more solute and less water compared to the other solution.

What would happen? What would happen if…

You placed a selectively permeable membrane “bag” with a hypotonic solution into a beaker with a hypertonic solution?

Which way would the water flow? What would happen to the bag? What would happen to the beaker? How do you know? How could you test this?

Facilitated Diffusion Diffusion with the help of transport

proteins No energy required http://www.stolaf.edu/people/giannini/flash

animat/transport/channel.swf

Active Transport Cell uses energy Actively moves molecules to where they

are needed Movement from an area of low

concentration to an area of high concentration

3 MAIN TYPES: 1. Protein pumps2. Endocytosis (BULK TRANSPORT)3. Exocytosis (BULK TRANSPORT)

Types of Active Transport1. Protein Pumps -transport proteins that

require energy to do work Example: Sodium / Potassium Pumps are

important in nerve responses. http://www.stolaf.edu/people/giannini/flashani

mat/transport/secondary%20active%20transport.swf

Protein changes shape to move molecules: this requires energy!

Types of Active Transport2. Endocytosis: taking bulky material into a

cell Uses energy Cell membrane in-folds around food particle “cell eating” Forms food vacuole & digests food This is how white blood cells eat bacteria!

Types of Active Transport3. Exocytosis: Forces material out of cell in

bulk membrane surrounding the material fuses

with cell membrane Cell changes shape – requires energy EX: Hormones or wastes released from cell http://www.stolaf.edu/people/giannini/flashani

mat/cellstructures/phagocitosis.swf

Photosynthesis

Energy and Life Energy = ability to do work Source of energy on Earth = sun Autotrophs use light energy from the

sun (or other sources) to make food. Heterotrophs obtain energy from foods

consumed. Energy comes in many forms

Light, heat, and electricity

ATP “like a fully charged battery” One of the principle chemical compounds

that is used to store energy Adenosine triphosphate (ATP)

ADP “like a ½ charged battery” When energy is released from ATP

converts to ADP and a phosphate group

Using Biochemical Energy Cells use this energy for:

Mechanical work, chemical work, transport work

Basically, all cellular processes ATP in cells = good for only a few seconds

of activity (not efficient storage) 1 molecule of glucose stores more than 90x’s

the chemical energy of ATP Cells can generate ATP as needed from the

glucose in carbohydrates consumed during feeding

Investigating Photosynthesis Jan van Helmont

Concludes plants gain most of their mass from water

Joseph Priestly Concludes that plants release a substance that

keeps a candle burning (oxygen) Jan Ingenhousz

Concludes that plants produce oxygen bubbles in the light but not in the dark (they need sunlight).

Photosynthesis Equation

Light and PigmentsPhotosynthesis requires: Light

From sunlight (A mixture of different wavelengths of light)

Chlorophyll (a pigment found in chloroplasts that absorbs light energy) 2 main types:

Chlorophyll a (absorbs violet and red light) Chlorophyll b (absorbs blue and red light)

Structure of a Chloroplast

NADPH When sunlight hits chlorophyll a double

bond is broken releasing a high energy electron.

This high energy electron requires a special carrier called NADP+.

Once the electron is combined with NADP+ it becomes NADPH.

NADPH carries this energy to other reactions around the cell.

Light-Dependent Reactions Use energy from sunlight to produce

Oxygen, ATP and NADPH. Photosystem II is the first to absorb light

(discovered after photosystem I) Light smashes high energy electrons out of the

chlorophyll molecules which are carried to electron transport chains in the thylakoid membrane.

The lost electrons from the chlorophyll molecule are replaced by breaking water molecules apart which releases oxygen.

Light-Dependent Reactions (Continued) High energy electrons move from

Photosystem II to photosystem I. Energy from this transport pumps H+ ions from

the stroma into the inner thylakoid. Pigments in photosystem I use sunlight to

release additional high energy electrons and a H+ ion becomes NADPH

Inside of thylakoid membrane becomes positively charged (from the H+ ions)/outside negatively charged Charge difference allows ATP to be made.

Light-Dependent Reactions (Continued) ATP formation=

H+ ions move through a protein called ATP synthase.

As it rotates the protein binds ADP with an additional phosphate to create ATP!

The Calvin Cycle:OR the light-independent reactions ATP and NADPH from the light reactions are

required to produce high-energy sugars. Step 1: CO2 enters the cycle and is combined with

6 5-Carbon molecules forms 12 3-Carbon molecules

Step 2: Energy from ATP and NADPH are used to convert the 12 3-Carbon molecules into higher-energy forms

The Calvin Cycle:OR the light-independent reactions Step 3: 2 3-Carbon molecules are used to

make a 6-Carbon sugar (glucose!) Step 4: The 10 remaining 3-Carbon

molecules are converted back into 6 5-carbon molecules These are reused in the next cycle!!!

Factors affecting photosynthesis Availability of Water

Shortage of water can slow or stop photosynthesis Temperature

Plants function best between 0°C and 35°C (temperatures above or below may damage enzymes and slow or stop photosynthesis)

Intensity of light Increasing intensity increases rate of photosynthesis

until maximum rate of photosynthesis is reached.

Photosynthesis Molecular Workbench We will be completing this online

together…Use your analysis packets as additional notes. We will be completing this in class!

Cellular Respiration

Chemical Pathways Energy in food:

Calorie = amount of energy needed to raise the temp. of 1 g of water 1°C

Gradually release energy from glucose and other food compounds

2 Pathway for energy release Aerobic (O2 present) Anaerobic (in the absence of O2)

Cellular Respiration Overview

Oxygen + glucose carbon dioxide +water +energy

6O2 + C6H12O6 6CO2+ 6H2O + ATP

3 main stages: Glycolysis The Krebs cycle (or “citric acid cycle”) Electron Transport Chain (or “oxidative

phosphorylation”)

Glycolysis (glyco- = sweet; lysis = breaking) Occurs in the cytoplasm near the mitochondion No oxygen is required for glycolysis 1 molecule of glucose (6C) is broken into 2

molecules of pyruvic acid (3C) (pyruvate) Needs to use 2 ATP to get started Generates 4 ATP at the end Net ATP total = 2 ATP

Produces 4 molecules of NADH (high energy electron carrier) transports to other reaction sites

What happens if there is no oxygen? Fermentation!

Cells convert NADH back into NAD+ by passing electrons back to pyruvate

Allows glycolysis to continue to produce ATP (not efficient)

2 main types: Alcoholic Fermentation (bacteria and yeast) Lactic Acid Fermentation (humans)

Alcoholic Fermentation Yeasts and bacteria Beer, wine, and bread production Pyruvic acid + NADH alcohol +

CO2 +NAD+

In bread: CO2 makes the bread rise Alcohol is baked off

Lactic Acid Fermentation Pyruvic acid is converted to lactic acid

This regenerates NAD+ so glycolysis can continue to generate ATP

Pyruvic acid + NADH lactic acid + NAD+

Produced in the muscles when there is not enough O2 causing burning/pain Example: Wall sit of death

What if there is oxygen present after glycolysis? Krebs cycle and electron transport chain!!! Most powerful electron acceptor =

oxygen!!! Uses the remaining 90% of energy still

trapped in the glucose molecule after glycolysis!

The Krebs Cycle Step # 1:

Pyruvic acid enters the mitochodrion A carbon is removed forming CO2 and electrons

are removed forming NADH CO2 is combined with coenzyme A and is

transformed into acetyl-CoA Acetyl-CoA adds a 2-C acetyl group to a 4C

compound forming citric acid.

The Krebs Cycle (continued) Step # 2:

Citric acid is broken down into a 5C compound then a 4C compound

2 molecules of CO2 are released, electrons form NADH and FADH2, and 1 ATP is generated

From one molecule of pyruvic acid= 4 NADH, 1 FADH2, 1 ATP But remember 2 molecules of pyruvic acid are made

from each molecule of glucose!!! (so this process happens twice)

Electron Transport The high energy electrons in FADH2 and

NADH from the Kreb’s cycle Are transported to the inner membrane of the

mitochondrion In prokaryotes ETC is in the cell membrane

The ETC uses the high energy electrons to make ATP

Electron Transport (continued) High energy electrons are passed to a series of

carrier proteins in the membrane As electrons move to each carrier, H+ ions are moved to

the inner membrane space These will be used later to generate ATP via ATP

synthase At the end an enzyme that combines the

electrons with hydrogen ions and oxygen to form water

Energy Totals Aerobic Respiration = 36 ATP

Uses 38% of the total energy of a molecule of glucose

The rest is released as heat (body heat!) More efficient than a gasoline car engine We are an efficient combustion engine!!!

Anaerobic Respiration = 2 ATP

Energy and Exercise Quick energy (a sprint)

ATP is short-lived and is used right away Stored ATP used in a few seconds of intense

activity Then, ATP is generated via lactic acid

fermentation

Energy and Exercise Long-term energy (marathon)

For exercise longer than 90 seconds cellular respiration is the only way to generate enough ATP to sustain activity.

Stored energy = glycogen (breaks down into glucose and is stored in muscles)

Lasts only about 15-20 minutes Once glycogen is depleted body uses fat

stores (good for weight loss!)

Linking to Homeostasis Rate of Cellular Respiration Inquiry (RITES

lab using BIOPACS) Heart Rate Monitor Design an experiment to test the rate of

cellular respiration How does cellular respiration work to

maintain homeostasis in the human body? Include body systems in your response.

Comparing Cellular Respiration to Photosynthesis Generate a chart comparing the following:

Photosynthesis Cell Respiration

Function

Location

Reactants

Products

Equation

Cellular Respiration Molecular Workbench Complete this online and use your analysis

packets as additional notes. We will be completing this in class!

TedX talk –Discovering ancient climates in oceans and ice: Rob Dunbar on TED.com

Cell Growth and Division

Limits to Cell Size Activity Draw an example of a town with the

borders being the edges of the paper There is one main road into and out of the

town. Think of a cell and the parts needed to run the

cell. Recreate these parts as parts of a town Don’t forget: nutrients (food trucks) and

waste (dump trucks)

Limits to Cell Size Activity Increase the Population by THREE TIMES What does this do to the demands put on

the town?: What does this do to the Traffic? What does this do to the Waste and Nutrients? What does this do to the Resources needed to

thrive? What does this do to the people who run the

town?

Limits to Cell Size Activity Based on the activity…

What are the 2 limits to cell size?What happens when a cell becomes

too big?

Cell Growth 2 limits to cell size =1. The larger the cell becomes the more demands

the cell places on its DNA2. The cell has difficulty moving nutrients and

waste across the membrane Thus the size of a cell is limited

As the length of a cell increases… Volume increases faster than its surface area

What happens when a cell gets too big? IT DIVIDES!!! Cell division

1 cell 2 daughter cells (exact copies of the original)

Prokaryotes easy Circular DNA copies then divides

Eukaryotes more involved Complex DNA (23 pairs of chromosomes =

46 total)

The Cell Cycle Average

time = 16 – 20

hours

G1 Phase Cell Growth

Intense growth and activity Increases in size Synthesizes new proteins and organelles

The Cell Cycle

S Phase DNA Synthesis

Creates a duplicate set of chromosomes G0 (or R on diagram) = Point of no return

Chromosome Structure

“supercoils”

Human Chromosomes (Karyotype)

The Cell Cycle

G2 Phase Preparation for Mitosis

Shortest of the 3 phases of interphase (G1, S, and Gs)

Organelles and proteins needed for cell division are produced.

The Cell Cycle

Mitosis Prophase Metaphase Anaphase Telophase Cytokinesis

Prophase Chromosomes condense (“appear”) Nuclear envelope dissolves Centrioles move to opposite sides (poles) of

the cell

Metaphase Centrioles send out spindle fibers that attach to

the chromosomes Chromosomes are lined up in the middle of the

cell

Anaphase Chromosomes (sister chromatids) are

pulled apart and move to the poles.

Telophase/Cytokinesis Occurs simultaneously Telophase

The nuclear envelope reforms around the chromosomes

The chromosomes uncoil Cytokinesis

The cytoplasm divides 2 daughter cells are produced (each are exact

copies of the original with 46 chromosomes)

What stages are these cells in?

Investigating Cell Reproduction Complete the lab activity

Paper lab

GO TO Meiosis PowerPoint

Regulating the Cell Cycle

Controls on Cell Division Cell growth and division can be turned on

and off Example

Cells in a petri dish will continue to grow until they come in contact with other cells.

A cut in the skin will cause cells to divide until the wound in healed.

Cell Cycle Regulators Cyclin

Protein that regulates the cell cycle in eukaryotic cells

When injected into a non-dividing cell it causes a mitotic spindle to form

Internal Regulators Responds to events inside the cell Makes sure that a cell does not enter mitosis

until all chromosomes are replicated

Cell Cycle Regulators (cont.) External Regulators

Respond to events outside the cell “Growth factors” that speed up or slow down

growth and division

Uncontrolled Cell Growth CANCER –

Cells that lose the ability to control cell growth Most cancers have damage to the p53 gene

Normally halts the cell cycle until all chromosomes are replicated

Chromosome damage builds up and the cancer cell loses the information that controls normal cell growth

Tumors masses of cells that can damage the surrounding tissue

CAUSES: smoking tobacco, radiation exposure (UV, XRAY, etc.), viral infection

Life Spans of Various Human CellsCell Type Life Span Cell DivisionLining of esophagus 2-3 days Can divide

Lining of small intestine

1-2 days Can divide

Lining of large intestine

6 days Can divide

Red blood cell Less than 120 days Cannot divide

White blood cell 10 hours to decades Cannot divide

Smooth muscle Long-lived Can divide

Cardiac (heart) muscle

Long-lived Cannot divide

Skeletal muscle Long-lived Cannot divide

Neuron (nerve cell) Long-lived Most do not divide

Life Spans of Human Cell Questions White blood cells help protect the body from

infection and disease-producing organisms. How might their function relate to their life span?

If cancer cells were added to the table, predict what would be written under the “Life Span” and “Cell Division” columns. Explain you’re the reasoning behind your predictions.