Anatomy of the Cell

Question 1

What features are common to all eukaryotic cells?

Answer 1

An outer membrane
An inner cytosol
A cytoskeleton
Membrane bound organelles
Inclusions

Question 2

What is the plasmalemma?

Answer 2

a phospholipid bilayer which separates the cytoplasm from the outer environment

Question 3

What is special about the plasmalemma?

Answer 3

it is amphipathic

it is selectively permeable

Question 4

What can be found in the plasmalemma?

Answer 4

cholesterol
integral proteins
transmembrane proteins

Question 5

What organelles can be found in the cytoplasm?

Answer 5

Mitochondria
RER
SER
Golgi apparatus
Lysosomes
Nucleus
Inclusions

Question 6

What is the function of the mitochondria?

Answer 6

energy production

Question 7

What is the function of the RER?

Answer 7

protein synthesis

Question 8

What is the function of the SER?

Answer 8

cholesterol and lipid synthesis

Question 9

What is the function of the golgi apparatus?

Answer 9

modification and packaging of secretions

Question 10

What is the function of lysosomes?

Answer 10

hydrolytic enzymes for intracellular digestion

Question 11

What are the three main classes of filaments in the cytoskeleton?

Answer 11

microfilaments - actin
intermediate filaments - 6 classes of protein
microtubules - a & b tubulin

Question 12

What are the functions of microtubules?

Answer 12

to move intracellular organelles and vesicles around the cell

Question 13

What do microtubules associate with to move?

Answer 13

kinesin - towards cell periphery

dynein - towards cell centre

Question 14

Where is the nucleus found?

Answer 14

in a nuclear envelope with inner and outer membranes and nuclear pores

Question 15

What is the nuclear envelope continuous with?

Answer 15

the RER and is studded with ribosomes

Question 16

what is the nucleolus?

Answer 16

a 1-3µm dense area within the nucleus

Question 17

define euchromatin

Answer 17

DNA that is actively undergoing transcription

Question 18

define heterochromatin

Answer 18

DNA that is condensed and not undergoing transcription. tightly wound and appears as dark splotches in the nucleolus

Question 19

where are ribosomes formed?

Answer 19

nucleolus

Question 20

What are ribosomes made up of?

Answer 20

small and large subunit

Question 21

What does the small unit of ribosomes do?

Answer 21

binds RNA

Question 22

What does the large unit of the ribosome do?

Answer 22

catalyses formation of peptide bonds

Question 23

Where is SER common?

Answer 23

in cells that synthesise cholesterol

Question 24

Where is RER common?

Answer 24

in active cells that produce lots of proteins i.e. plasma cells –> antibodies

Question 25

How might the golgi apparatus modify molecules?

Answer 25

add sugars cleave glycosylate move into granules or vacuoles

Question 26

what is special about mitochondria?

Answer 26

contain their own DNA which is passed on from the mother

Question 27

Where are the most mitochondria found?

Answer 27

in cells which require lots of protein and lipid synthesis i.e. liver and muscle cells

Question 28

What are the three types of intercellular junction?

Answer 28

Occluding Anchoring Communicating

Question 29

What is the function of occluding junctions?

Answer 29

formation of a diffusion barrier

Question 30

Where would you find an occluding junction?

Answer 30

at the apical membrane of the cell

Question 31

What are occluding junctions also known as?

Answer 31

tight junctions, zona occludens

Question 32

What is the function of the anchoring junctions?

Answer 32

to provide mechanical strength especially where cells are likely to undergo stretch

Question 33

What are desmosomes?

Answer 33

anchoring junctions which are common in skin; link via cadherin molecules

Question 34

What are hemi-desmosomes?

Answer 34

molecules which link submembrane filaments of a cell to the EC matric through transmembrane proteins

Question 35

What is another name for communicating junctions?

Answer 35

gap junctions

Question 36

What is the subunit of the gap junction?

Answer 36

connexins

Question 37

Where are gap junctions found?

Answer 37

in epithelia and smooth and cardiac muscle

Question 38

In what ways can material move across the cell membrane?

Answer 38

``` diffusion transport proteins vesicles endocytosis phagocytosis ```