Week 2: The Cell Flashcards
(50 cards)
1
Q
What are the 4 components in the cell theory
A
- cells are the building blocks of all organisms
-all cells come from the division of prexisiting cells - cells are the smallest unists that perform all vital physiological functions
- each cell maintains homeostasis at the cellular level
2
Q
What are the 5 functions of the plasma membrane
A
- physical isolation : barrier
- regulation of exchange with the environment: ions and nutrient enter, wastes elimianted/cellular prods released
- sensitivity to environment: extracellular fluid composition and chem signals
- structural support: anchor cells+tissues
3
Q
Describe the strucuture of the plasma membrane
A
- a phospholipid bilayer
- hydrophillic heads face outwards toward water envionrments
- hydrophobic fatty acid tails- inside membrane
- barrier to ions and water soluble compounds
4
Q
8 types of membrane proteins
A
- integral(inside)
- peripheral(inside/or outer)
- achoring(stabilizers-inside/out of structures)
- recognition(identifiers-label own cells and outside cells)
- enzymes(catalyze reaactions)
- receptor(bind and respond to ligands(ions/hormones)
- carrier(transport specific solutes thru)
- channels(regulate water flow+solutes passing thru membrane, open or close to regulate passage of subtances)
5
Q
3 types of membrane carbohydrates
A
- proteogylycans, glycoproteins,glycolipids
- extend outside of membrane
- form sticky sugar coat(glycocalyx)
6
Q
4 Functions of glycocalyx
A
- lubrication+protextion
-anchoring+locomotion)
-specifity in binding to receptors - recognition(immune response)
7
Q
Describe the structure of cytoplasm
A
- contains all material inside the cell+cytosol(intracellular fluid)
- nutrients,ions,proteins,waste products (dissolved)
- high protein and potassium lvls
- low carbs,lipid.amino acid, Na+ lvl
8
Q
Describe the two types of organelles, and 7,5 examples
A
- nonmembranous
-> no membrane - direct contact w cytosol
- cytoskeleton, centroiles,ribosomes,proteasomes,microvilli,cilia,flagella
-membranous
->isolated from cytosol by plasma membrane
->endoplasmic reticulum, golgi apparatus, lyosoymes, peroxisomes, mitochondria
9
Q
What are Cytoskeletons
A
structural proteins for shape and strength
- micro fillaments, intermediate fillmaents, microtublets
10
Q
What are microfillaments
A
- thin filaments made of protein actin
- provide mechanical strength
- interact w proteins to adjust consistency of cytosol
- and w thick myosin filaments for muscle contraction
11
Q
What are intermediate filllaments
A
- mid sized between microfillaments and microtubules
- durable
- strengthen the cell+maintain shape
- stabilize organelles position
- stabilize cell position
12
Q
What are microtubules
A
- large hollow tubes of tubulin proteins
- attach to centrosome
- strengthen cell+Anchor organelles
- change cell shape
- move organelles w help of motor proteins
- form spindle apparatus to distribute chromosomes
- form centrioles and cilia of organelles
13
Q
What are microvilli
A
- increase surface area for absorption
- attach to cytoskeleton
14
Q
What are centrioles
A
- form spindle apparatus during cell divison
- surrounded by centrosomes - cytoplasm nes to nucleus
15
Q
What is cillia
A
- extensions of plasma membrane
- move fluids across cell surface
- primary cillium=nonmotile-
-> senses environmental stimuli - moitle cilia cells line respiratory+reproductive tracts
->microtubulus in cilia anchored to a basal body - flagellum is tail-like extension of cell membrane
16
Q
Structure and function of ribosomes
A
- organlles that synthesize proteins
- composed of small+large ribosomal subunits
->contain rRNa - free ribsome in cytoplasm=manafacture proteins->enter cytosol
- fixed ribsomes attach to ER-manafacture proteins->enter ER for packaging
17
Q
Function of proteasomes
A
- contain enzymes (proteases)
- dissassemble damaged proteins for recylcing
18
Q
2 types of endoplasmic reticulum, and 4 functions
A
- contains storage chambers = cisternae
- smooth+rough(SER+RER)
- synthesis of proteins,carbs,lipids
- storage of synthesised molecules and materials
- transport of materials within the er
- detoxification of drugs or toxins
19
Q
What is smooth ER and 4 functions
A
- no ribosomes attached
- synthesizes
-> phospholipids+cholestorol(for membranes)
->steriod hormones(for reproductive systems)
->glycerides(storage in liver+fat cells)
->glycogen(storage in mucscle_liver cells)
20
Q
what is rough ER and 3 functions
A
- surface covered w ribosomes
- active in protein nd glycoprotein synthesis
- folds proteins in secondary+teritary strcutures
- encloses products in transport vesicles for delivery to golgi apparitus
21
Q
what are golgi apparitus and 4 functions
A
- where vesicles enter forming face, exit maturing face
- modifies and packages secretions(hormones,enzymes)for release from cell
- adds or removes carbs to or from proteins
- renews or modifies plasma membrane
- packages special enzymes w vesicles for use in cytoplasm
22
Q
what are lysosymes and 2 types
A
- enzyme containg vesciles produced by golgi apparatus
- desotry bacteria,break down molecules, recyle damages organelles
- primary lysosymes
->contain inactive enzymes
-secondary lysosymes
->formed when primary lys fuse w damages organelles+enzymes r activated
23
Q
What is autolysis
A
- self destruction of damaged or inactive cells
- lysosyme membrane breaks down
- digestive enzymes released
- cell destroyed
- cellular materials digested
24
Q
What are peroxisomes+ 3 function
A
-small,enzyme containing vesicles
- produced by division of of existing perixosomes
- break down organic compounds such as fatty acids
- produce the free radical hydrogen peroxide
- catalase converts hydrogen peroxide to oxygen and water
25
What is the mitochondria and function
-smooth outer membrane
-inner membrane has numerous folds(Cristae)
- cristae surround fluid contents
- take chemical energy from food (glucose)-> produce energy molecule ATP
26
4 processes that produce mitochondrial energy
- Glycolysis: glucose to pyruvic acid(in cytosol
-> mitochondria absorb pyruvate molecules
- ctric acid(krebs) cycle: occurs in mitochondrial matrix
->breaks down pyruvate
- electron transport chain:inner mitochondrial membrane
- aerobic metabolism(cell rep): mitochondria use oxygen to break down food and prod ATP
-> prod 95% of atp needed to keep cell alive
->glucose+oxygen+ADP->co2+h20+atp
27
Describe structure and function of the nucleus
- largest organele
- cells control centre
- nuclear envelope=double membrane around the nucleus
- perinculear space=between 2 layers of nuclear envelope
- nuclear pores= communication passages in nuclear envelope
28
Describe the 3 structures inside nucleus and their fucntions
- nuclear matrix in nucleoplasm: support fillaments
- nuceoli: nuclear organelles
-> synthesize rRNA+ assemble subunits
- >made of rna enzymes histones
- nucleosome: DNA coiled around histones
->loosely coiled into chromatin in nondividing cells
->tighlt coiled chromosomes form before divison
29
What information is stored in the nucleus
- genetic code
->chemical language of dna instructions
->sequence of bases (A,G,T,C)
-> triplet code:3 bases, 1amino acid
- gene
-> DNA instructions for one protein
->functional unit of heredity
30
Define permeability
- determines what moves in or out of a cell
- allows nothing in/our=impermeable
- allows anything to pass =freely permeable
- restricts movement =selectively permeable(plasma membrane; restricts based on size,e charge, shape,lipid solubility)
31
Transport processes through plasma membrane
- passive processes(no energy)
-active processes(energy)
- diffusion+osmosis(passive)
- carrier mediated transport(passive or active)
- vasiuclar transport(Active)
32
What is diffusion
- movement of a substance from area of higher concentration to area of lower concentration
- ions and molecules are constantly in motion
->molecules in solution move randomly
->random motion causes mixing
33
What is concentration gradient
-diff betnween high and low concentrations of a substance
34
What are the 5 factors influencing diffusion
- distance the particle has to move
- ion and molecule size
->smaller=faster diffusion
- temperature
->more heart=fast diffusion
-concentration gradient
->steeper grad=faster diffusion
-electrical forces=opposites attract, like repel
- presence of channel proteins
35
2 types of diffuson and molecules/susbtances involved
-simple diffusion
->lipid soluble compounds(alcohol, steroids,fattyacids)
->dissolved gasses(o2,co2)
->water molecules
-channel mediated diffusion
->water soluble compounds and ions
->affected by size, charge, interaction w channel walls
36
Describe the process of osmosis
- is diffsion of water across a selectively permeable membrane
- water molecules diffuse across a membrane toward solution w more solutes
- occurs more rapidly than slute diffusion
->as water can pass thru a membrane thru abundant water channels(aquaporins
->aquaporins>solute channels
37
What is osmotic pressure
- force with which pure water moves into a solution as a result of solute concentration
-hydrostatic pressure is pressure needed to block osmosis
38
What is tonicity and 3 types
- describes how a solution affects a cell
- isotonic solution-> does not cause osmotic flow
-hypotonic solution->lower solute concentration than the cell
-hypertonic solution->higher solute concentration than the cell
39
Cells in 3 diff types on tonicity solutions
- in a isotonic solution
->stays the same size and solution
-cell In hypotonic solution
->gains water+may rupture(hemolysis)
-cell in hypertonic solution
->loses water and shrinks(creation)
40
What is carrier mediated transport
- proteins tranport ions or organic substances across plasma membrane
- rate depend on availability of transport proteins +substrates
-cofactors such as hormones affect activity of carriers
41
What is symport
cotransport
two substances move in same direction at same time
42
what is antiport
-countertransport
one substnace moves in while one moves out
43
Describe facillitated diffusion
- passive
- movement of molecules across a membrane by carrier protein
- molecules too large too fit thru channel proteins(glucose,amino acids)
- molecule binds to specific receptor site on carrier protein
- protein shape changed,molecule difuses thru
44
Describe primary active transport
- carrier proteins pumping substances against a conc grad using atp
- sodium potassium echange pump
->one atp powers the movement of 4 na+ ions and two k+ ion in
45
What is vesicular transport and the 4 types
- materials move in or out of cell in vesicles
- endocytosis:importation of extracellular materials packaged in vesicles, requires atp
->receptor mediated endocytosis
->pinocytosis
->phagocytosis
46
What is receptor mediated endocytosis
receptors(glycoproteins) bind target molecules(ligands)
-receptors and their ligands migrate to clathrin-coated pits of plasma membrane to enter cell
-some receptors are associated with membrane lipids and small indentations called caveolae
47
what is pinocytosis
endosomes “drink” extracellular fluid. involves the intake of extracellular fluids and small dissolved molecules through small vesicles
48
what is phagocytosis
involves the engulfment of larger particles, such as bacteria or cell debris, within larger vesicles called phagosomes
49
what is exocytosis
granules or droplets are released from the cell as a vesicle fuses to plasma membrane
50
what is membrane potential
- when positive and negative charges are separated, a potential difference is created
-unequal charge across the plasma membrane is membrane potential
-resting membrane potential ranges −10 mv to −100 mv, depending on cell type
