Cell biology

Question 1

what are the two types of prokaryotes

Answer 1

Bacteria and archaea

Question 2

what are the benefits of organisms being multi cellular

Answer 2

longer lifespan, better adaptation, fewer predators

Question 3

what 2 components is cytoplasm composed of?

Answer 3

cytosol and organelles

Question 4

what is cytosol and what is it the site for?

Answer 4

intercellular fluid that contains dissolved ions, glucose, amino acids, ATP, lipids and water.
And its the site for enzyme reactions

Question 5

what is the cytoskeleton?

Answer 5

dynamic structure which is constantly reorganised as the cell changes shape (e.g. during the segregation of chromosomes)

Question 6

what is the cytoskeleton responsible for

Answer 6

large scale movements, such as contraction of muscles

Question 7

what are the 4 stages of the movement of actin

Answer 7

protrusion, adhesion, deadhesion, movement

Question 8

what are intermediate filaments specialised for

Answer 8

bearing tension

Question 9

what are microtubules constructed of

Answer 9

globular proteins, tubulin

Question 10

what are the 3 components of the cytoskeleton

Answer 10

actin monomer, intermediate filament, microtubule

Question 11

why do actin monomers cover the outer layers of the cytoskeleton

Answer 11

as they’re highly responsible for movements and contractions of muscles

Question 12

what disorders are associated with cytoskeleton defects

Answer 12

skin conditions, neuropathies (alzheimers)

Question 13

what does less cilia cause people to become more susceptible to?

Answer 13

infection

Question 14

what are the structures of the nucleus

Answer 14

nucleolus, chromatin, nuclear membrane, nuclear pore

Question 15

what is the endoplasmic reticulum

Answer 15

a network of membranes in the form of flattened sacs and tubules extending from the nuclear envelope

Question 16

what is the rough ER the site for

Answer 16

protein synthesis

Question 17

what is the smooth ER the site for

Answer 17

synthesis of fatty acids and steroids - in the liver it helps release glucose from glucose - 6 - phosphate and detoxify drugs such as alcohol

Question 18

what do ribosomes consist of

Answer 18

A large subunit made of 60S eukaryotes and small subunit 40S eukaryotes - each is rich in ribosomal RNA and contains over 50 protiens

Question 19

what are the 3 areas of the Golgi and where are they located?

Answer 19

Cis- faces the ER, Medial- between the cis and trans, Trans - faces the plasma membrane

Question 20

what are the 3 different types of endosomes

Answer 20

early, late, recycling

Question 20

what are endosomes

Answer 20

a collection of intracellular sorting organelles in eukaryotic cells

Question 21

what is the function of endosomes

Answer 21

sorting proteins to their final location

Question 22

what is mitochondria the site of

Answer 22

aerobic respiration

Question 22

what is autophagy

Answer 22

the digestion of substances entering the cell or worn out cells

Question 23

what is autophagy required for

Answer 23

renewal and control of growth & tissue remodelling

Question 23

what is Tay-Sachs disease

Answer 23

an inherited condition that affects children, caused by the absence of lysosomal enzyme Hex A - causes seizures and blindness

Question 24

what is a peroxisome

Answer 24

derived from the ER, contains oxidases and are involved in amino acid and fatty acid metabolism

Question 25

what disorder is linked to dysfunctional mitochondria

Answer 25

Parkinson's

Question 26

how does cholesterol help the membrane maintain fluidity

Answer 26

reduces fluidity at modern temperature, reduces solidification at low temperatures

Question 26

why is transport across membranes important

Answer 26

to regulate the concentrations from outside o the inside of the cell

Question 26

which area of a phospholipid is hydrophobic and which is hydrophilic

Answer 26

the head is hydrophilic and the tails are hydrophobic

Question 26

can lipid bilayers be asymetrical

Answer 26

yes

Question 26

what helps maintain membrane fluidity

Answer 26

cholesterol

Question 27

why does the body need a fluid membrane

Answer 27

to allow movement,

Question 27

what is passive transport

Answer 27

molecules moving down a concentration gradient, doesn't require energy

Question 27

what molecules move via facilitated diffusion

Answer 27

large uncharged molecules, ions

Question 27

what does the level of symmetry between the lipid bilayers say about the health of a cell

Answer 27

the more symmetrical the unhealthier/dying a cell is

Question 27

what molecules can move via simple diffusion

Answer 27

hydrophobic and small, uncharged molecules

Question 28

what is osmosis

Answer 28

the movement of water down a water potential gradient through a partially permeable membrane through aquaporins in the lipid bilayer

Question 28

what are the cell shapes that change with the concentration of water

Answer 28

hypertonic, isotonic, hypotonic

Question 28

what is active transport

Answer 28

movement against a concentration gradient, requires energy

Question 29

what are the two types of passive transport

Answer 29

diffusion and facilitated diffusion

Question 30

what does it mean when a cell is hypertonic

Answer 30

the cells have shrivelled due to water leaving the cell

Question 31

what does it mean when a cell is isotonic

Answer 31

when the water level is balanced outside and inside the cell, so shape remains the same

Question 31

what does it mean when a cell is hypotonic

Answer 31

when cells lyse/ burst as too much water enters the cell

Question 32

what 2 types of proteins are used in facilitated diffusion

Answer 32

carrier and channel

Question 33

what molecules do channel proteins transport

Answer 33

small and highly selective molecules

Question 34

what molecules do carrier proteins transport

Answer 34

large and highly selective molecules

Question 35

what are the 3 types of gated ion channels

Answer 35

volage gated, ligand gated, mechanically gated

Question 36

what are the 2 main types of membrane proteins

Answer 36

integral and peripheral

Question 37

what are the 3 types of integral proteins and what are their uses

Answer 37

a-helix (receptors), helical bundle (enzymes and transporters) and b-barrel (channel proteins)

Question 38

what are the 3 types of facilitated diffusion carriers

Answer 38

uniport, symport and antiport

Question 39

the glucose transporter (GLUT) is an example of what type of diffusion

Answer 39

facilitated diffusion

Question 40

what is cystic fibrosis caused by

Answer 40

defective chloride ion transport causing a build up in sodium inside the cells causing an increase in osmosis

Question 41

what are first 1-3 stages of the insulin dependant glucose uptake system

Answer 41

1- insulin binds to an insulin receptor 2- phosphorylation of insulin receptor substrate1 (IRS-1) 3 - IRS-1 activates PI 3-kinase

Question 42

what are he stages 4-6 in the insulin dependant glucose uptake system after PI 3-kinase has been activated

Answer 42

4- activated PI 3-kinase activates GLUT4 5 - GLUT4 facilitates uptake of glucose into the cell 6 - glucose is converted to energy in the mitochondria

Question 43

what is primary active transport

Answer 43

the moving of ions by the hydrolysis of ATP