Upload
benedict-gray
View
221
Download
0
Embed Size (px)
Citation preview
Field of View
Fly’s Foot
Surface of an Erasable Programmable Read-Only Memory
Silicon microchip
Eyelash hairs growing from the surface of human skin
The surface of a strawberry
Bacteria on the surface of a human tongue
Human sperm (spermatozoa)
Nylon hooks and loops of Velcro
Household dust: includes long hairs of cat fur, twisted synthetic and woolen fibers,
serrated insect scales, a pollen grain, and plant and insect remains
The weave of nylon stocking fibers
The head of a mosquito
Head louse clinging to a human hair
Eight eyes (two groups of four) on the head of a tarantula
Cut human hairs and shaving foam between two razor blades
Cigarette paper the tobacco is rolled in
Corroded surface of a rusty nail
Mushrooms spores
Clutch of butterfly eggs on a raspberry plant
Calcium phosphate crystal
Spider Skin
Starch in a corn kernel
Intestinal Bacteria
Paramecium
Volvox
Hooke
Eukaryotes
FluidMoasicModel
http://multimedia.mcb.harvard.edu/anim_innerlife.html
Nucleus
Nucleus
• Contains the genes that control the cell; localizing the cell’s DNA
• Nuclear envelope
- separates the nucleus contents from cytoplasm
- double membrane with pores to regulate what enters and exits nucleus
Nucleus
• Nucleolus – densely packed RNA and proteins that makes up ribosomes
• Chromatin: threads of DNA that makes up the chromosomes and their associated proteins (histones)
Endomembrane System• Membranes physically touch one another
or transfer membrane segments through tiny vessicles
• Includes:- Nuclear envelope- Endoplasmic reticulum- Golgi apparatus- Lysosomes- Peroxisomes- Cell membrane
ER + Ribosomes
Endoplasmic Reticulum
• Membranous labryinth extending from the nuclear membrane
• Made of tubes and sacs called cisternae
Rough ER: ribosomes stud the cytoplasmic surface
• Many types of specialized cells secrete proteins made by the rough ER which are moved in transport vesicles
• As the polypeptide chain grows from the ribosomes, it goes into the ERs cisternal space and folds into higher levels
• Some proteins (glycoproteins) are covalently bonded to carbohydrates or are embedded in newly synthesized lipid membranes
Smooth ER: cytoplasmic surface lacks ribosomes
• Function:
- synthesis of phospholipids and steroids
-carbohydrate metabolism,
-detoxification of drugs/poisons
Ribosomes
• Sites where cells assemble proteins according to genetic instructions
• Free ribosomes are suspended in the cytoplasm which make proteins that will function in the cytosol
• Bound ribosomes are attached to the endoplasmic reticulum which make proteins that be included in membranes or transported outside the cell
Golgi Bodies
Golgi Apparatus
• Flattened, inner-connected membranous sacks with cisternae
• Products of ER are modified, stored, and shipped via transport vesicles
• Secretory vesicles have “docking sites” that recognize the surface of specific organelles
Lysosome
• Membrane-enclosed bag of hydrolytic enzymes that digests macromolecules
• Works best in an environment with pH = 5
• Amoeba eat via phagocytosis = engulf food then digest as the lysosome fuses to it
• Usually only found in animals
Animation: Lysosomes
Lysosome
Peroxisome
Peroxisome
• Contains enzymes that transfer hydrogen from various substrates to oxygen, producing H2O2
• The H2O2 is then converted into water
• Helps breakdown fats to be used in mitochondria for energy
• Detoxify alcohol in the liver
Mitochondria
Mitochondria
• Site of cellular respiration which generates ATP from sugars and fats
• Have ribosomes and small amounts of DNA for its own protein synthesis
• 100s-1000s per cell which correlate to the metabolic activity of the cell
• Enclosed in phospholipid bi-layer with inner foldings called cristae
Chloroplasts
Chloroplasts• Convert solar energy into chemical energy
by absorbing sunlight and using it to synthesize glucose from CO2 and H2O.
• Plastids: specialized organelles in plants- Leucoplasts: store starch in roots and tubers- Chromoplasts: enriched in pigments that give plants their colors- Chloroplasts: contain the green pigment cholorphyll
• What organelle is taking up most of the space in this plant cell?
Vacuole
• Central vacuole: stores water, organic compounds, ions, wastes, and hydrolytic enzymes
• Tonoplast: membrane surrounding plant vacuole
• Vacuoles and vesicles are both membranous sacs, but vacuoles are larger
Cytoskeleton
Cytoskeleton• Network of fibers that allow for material
movement within the cell• microtubules – larger filaments that help
• move organelles during cell division • form hair-like extensions on cell surface for
movement (cilia or flagella)• Centrioles – rings of microtubules which form
spindle fibers to aide in cell division
• Microfilaments (actin) – smaller filaments that maintain shape and aid in muscle contraction
Centriole
Flagella
Cell Wall
• Made of cellulose (polysaccharide) not digested by most animals
• Rigid structure that supports and protects plant cell by preventing the excess uptake of water- turgor pressure from vacuole assists in support
• Allows movement of materials in/out of cell through plasmodesmata (channels)
Cytoplasm
• Cytosol: semi-fluid medium in which organelles are suspended
• Mostly water but also contains ions, sugars, amino acids, RNA, and ATP (cell energy)
Harvard Cell Animation/
Plasmolyzed Flaccid Turgid
Animation of Endo/Exocytosis
Exocytosis