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Flashcards in Ch 2. Cells Deck (58):
1

Membrane proteins

1. peripheral (only attached to one side of the phospholipid bilayer) disrupt by salt cxn
2. Integral (imbedded inside the bilayer, ampiphatic) disrupt by using detergent
3. transmembrane (goes all the way through the bilayer and out both sides)

2

Phospholipid bilayer permeability

small, uncharged non-polar molecules (polar can only if its small and uncharged) and hydrophobic molecules can pass freely through the bilayer

3

Channel proteins

provides passage for hydrophilic substances that are charged and polar

4

recognition proteins

glycoproteins, oligosaccharide flags in order to distinguish from self and foreign

5

Ion channels

provides passage for ions, aka gated channels in nerve and muscle cells, they respond to stimuli
-voltage gated=difference in membrane potential
-ligand gated= chemical opens gate
-mechanically= opens by pressure, vibration etc

6

Porins

passage of certain ions and small polar molecules

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carrier proteins

binds to specific molecules, protein changes shape, molecule passes along. glucose into the cell is an EX.

8

Transport proteins

can use ATP to transport molecules, active transport, facilitated diffusion

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adhesion proteins

attach cells to neighboring cells, provides anchors for inter filaments and microtubules, stability

10

receptor proteins

binding site for hormones + other trigger molecules

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What is cholesterols role in the cell membrane?

add rigidity to animal cells under normal circumstances
-low temp>> maintains fluidity

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haponoids

does what cholesterol does in eukaryotic cells except for prokaryotic cells

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Glycocalyx

carbohydrate coat that covers outer face of cell wall of some bacteria and outer face of plasma membrane (some animal cells). may provide adhesion capabilities or barrier to infection

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chromatin

loose strands of DNA found in the nucleus

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chromosomes

tightly bound DNA which occurs when the cell is ready to divide

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histones

organize DNA, which raps around it into a bundle called NUCLEOSOMES (8) histones

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Nucleolus

inside nucleus, maker of ribosomes rRNA, completion happens outside the nucleus

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Nucleus

double layer nuclear envelope
- nuclear pores for transport
-nucleoplasm inside

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Nucleoid

blob inside prokaryotic cells that contains genetic info

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cytoplasm

metabolic activity and transport occur here, cyclosis is streaming movement within cell (the stew)

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Cytosol

just the gel substance (the jello)

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Ribosomes

bigger/heavier in eukaryotic cells, function is make protein

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Rough ER

creates glycoproteins by attaching polysaccharides to polypeptides
-in eukaryotes the rough Er is continuous with the outer nuclear membrane

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Smooth ER

synthesis of lipids and steroid hormones for export
-in liver= the smooth ER breaks down toxins and drugs by cellular rxns.

25

Lysosomes

- vesicles produced by the golgi apparatus
breakdown the trash, contain digestive enzymes

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Golgi

transport of various substances in vesicles has flattened sacs called cisternae

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peroxisomes

produces peroxide (can also break it down) and breaks down fatty acid and amino acid, common in the liver and the kidney

28

glyoxysomes

similar to peroxisomes in that it breaks down fatty acids, and allows seeds to germinate

29

Microtubules

provide motility and support for cellular activities, and provide the spindles for cell division in flagella and cilia (9+2 array 9 pairs plus a doublet in the center). made up of the protein tubulin

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Intermediate filaments

provide support for maintaining cell shape, keratin

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Microfilament

made up of actin and involved in cell motility

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Microtubules organizing centers

include centrioles and basal bodies (are at the base of each flagellum and cilium and organize their development). 9x3 array

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transport vacuoles

move materials between organelles or organelles and the plasma membrane

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food vacuoles

temporary receptacles of nutrients, merge with lysosomes to break down food

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central vacuoles

very large, occupy most of the space in a plant cell exert turgor when fully filled to maintain rigidness

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storage vacuoles

plants store starch, pigments, and toxins such as nicotine

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contractile vacuoles

single celled organisms that pump excess water out of the cell (prevent bursting)-found in protists and amebas

38

cell walls

found in plants, fungi, and protists-cellulose in plants chitin in fungi, peptidoglycan in protists, polysaccharides in archea provides support and protection

39

Extracellular matrix

space between cells, we see adhesion proteins, fibrous structural proteins, and polysaccharides, lots of collagen

40

plastids

plant cells
-Chloroplasts
-leucoplasts = store starch, lipids, and proteins
-chromoplasts = store carotenoids

41

Mitochondria

Make ATP, fatty acid catabolism (B-oxidation!) they also have their own DNA and ribosomes and they have a double layered membrane

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Cytoskeleton

microtubules, microfilaments, intermediate filaments Ex cilia and flagella, aids in support and movement of the cell

43

Intracellular circulation

Brownian movement- particles move due to kinetic energy, spreads small suspended particles throughout the cytoplasm
Cyclosis- circular motion of cytoplasm around cell transport molecules
ER- provides channel through cytoplasm, provides direct passage from plasma membrane to nuclear membrane

44

Extracellular circulation

Diffusion- cells that are in contact with external environment can suffice for food and respiration
Circulatory system- complex animals with cells to far from external environment require one, use vessels

45

Anchoring junctions/ desmosomes

(keratin filaments inside attach to adhesion plaques which bind adjacent cells together via connecting adhesion proteins, providing mechanical stability, hold cellular structures together

46

Tight junctions

completely encircles each cell, (stitched) producing a seal that prevents the passage of materials between cells; characteristic of cells lining the digestive tract where materials are required to pass through cells into blood (They prevent the passage of molecules and ions through the space between cells

47

Gap junction

narrow tunnels between animal cells (connexins); prevent cytoplasms of each cell from mixing, but allow passage of ions and small molecules; essentially channel proteins of two adjacent cells that are closely aligned (smooth muscle single of spreading action potential). In animal cells. Tissue like heart have these to pass electrical impulses

48

Plasmodesmata

narrow tunnels between plant cells (narrow tube of endoplasmic reticulum-
desmotubule; but exchange material through cytoplasms surrounding the desmotubule

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Prokaryotes

1. plasma membrane
2. naked DNA blob Nucleoid
3. ribosomes
4. cytoplasm
5. cell wall

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Bulk flow

collective movement of substances in the same direction due to a force in pressure ex. blood

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passive transport

-simple diffusion
-osmosis

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plasmolysis

movement of water out of a cell that results in its collapse

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countercurrent exchange

diffusion by bulk flow in opposite directions- blood and water in fish gills

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Endocytosis

uses ATP, active process and exocytosis is as well

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phagocytosis

undissolved material (solid) enters cells; white blood cell engulfs, plasma membrane wraps around (eating)

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pinocytosis

dissolved material that cell invaginates (drinks)

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receptor mediated

a form of pinocytosis; specific molecules (ligand) bind to receptors; proteins that transport cholesterol in blood (LDL) and hormones target specific cells by this.

58

aquaporins

increase rate of H2O passing (kidney and plant root cells) These tend not to be specific, they’re just large passages, if you can fit you’d go through.