Cell Structure & Organisation

Question 1

What does the cell membrane do?

Answer 1

Separates internal and external environments

Exocytose/endocytose to maintain constant cytosol composition

Selectively permeable

Question 2

What are the five types of proteins (with functions) of the cell membrane?

Answer 2

Transporters

Ion channels

Anchors

Receptors

Enzymes

Question 3

How does the amount of cholesterol affect the fluidity of a membrane?

Answer 3

More cholesterol = less fluidity (or vice versa)

Question 4

What are the two types of chromatin, which is active and how do they stain?

Answer 4

Euchromatin (active, pale-staining)

Heterochromatin (inactive, dark)

Question 5

What occurs in the nucleolus?

Answer 5

Ribosomes are transcribed and assembled

Question 6

What is the function of the smooth endoplasmic reticulum?

Answer 6

Detoxification and conjugation of noxious substances (liver)

Lipid and steroid metabolism (adrenal glands)

Glycogen metabolism

Membrane formation and recycling

Question 7

What processes is the rough endoplasmic reticulum associated with?

Answer 7

Protein synthesis

Initiation of glycoprotein synthesis

Question 8

Where are proteins transported to after the rER?

Answer 8

Golgi apparatus

Question 9

What is the function of the Golgi apparatus?

Answer 9

Sort and package proteins for transport

Question 10

How are triglycerides stored in cells?

Answer 10

Lipid droplets

Not membrane-bound

Question 11

What are specialised fat cells called?

Answer 11

Adipose cells/adipocytes

Question 12

Where is the nucleus in a fat-storing cell?

Answer 12

(Pushed to) periphery

Question 13

How thick are microfilaments?

Answer 13

7 nm

Question 14

What are the monomers of microfilaments?

Answer 14

G-actin

Question 15

What is the structure of a microfilament?

Answer 15

Two intertwined strands of actin (F-actin)

Question 16

How thick are intermediate filaments?

Answer 16

10 nm

Question 17

How thick are microtubules?

Answer 17

25 nm

Question 18

What are microtubules made up of?

Answer 18

Alpha and beta tubulin

Question 19

On which end is it easier to add/remove subunits?

Answer 19

Plus end

Question 20

What protein is responsible for retrograde transport of organelles via microtubules?

Answer 20

Dynein

Question 21

What protein is responsible for anterograde transport of organelles via microtubules?

Answer 21

Kinesin

Question 22

How long a microvilli?

Answer 22

1 micron/micrometre

Question 23

What is the cytoskeletal structure of microvilli?

Answer 23

Microfilaments which form a core running through each microvillus (anchored to actin cortex, other actin filaments and the cell membrane)

Question 24

How long are cilia?

Answer 24

Up to 10 microns/micrometres

Question 25

How many cilia can there be on a single cell?

Answer 25

Up to 300

Question 26

What is the function of cilia?

Answer 26

Move fluid (produced by goblet cells) over cell surface

Question 27

What is the function of microvilli?

Answer 27

Increase surface area for absorption

Question 28

What maintains the structure of a cilium?

Answer 28

Microtubules arranged in a ring of 9 doublets around a central pair (9+2)

Question 29

What kind of stem cells produce the blood cells?

Answer 29

Multipotent haemotopoietic stem cells

Question 30

What element of the cytoskeleton is responsible for movement of organelles in a neuron?

Answer 30

Microtubule

Question 31

What maintains the axon (of the cytoskeleton)?

Answer 31

Neurofilaments and microtubules

Question 32

What is the function of epithelia?

Answer 32

Cover exposed surfaces Line internal passageways/chambers Produce glandular secretions

Question 33

What is the function of connective tissue?

Answer 33

# Fill internal spaces Structural support Store energy (eg. In bone)

Question 34

What is the function of muscle tissue?

Answer 34

Contract to produce active movement

Question 35

What is the function of neural tissue?

Answer 35

Conduct electrical impulses (carry info)