Module 2:Cell structure

Question 1

What makes a cell eukaryotic

Answer 1

it contains a nucleus and membrane bound organelles

Question 2

What organelles are present in eukaryotic ultrastructure

Answer 2

nucleus
mitochondria
RER
SER
Golgi apparatus
ribosomes
centrioles
lysosomes

Question 3

What is the role of the nucleus and what structures are within it?

Answer 3

controls all cell activity by controlling the transcription of DNA
it contains a nucleoplasm which is full of chromatin , a nucleolus which synthesises ribosomes and a nuclear envelope which is a double membrane containing pores to allow movement of mRNA

Question 4

What is the role of the mitochondria and what structures does it contain

Answer 4

to produce ATP during aerobic respiration
surrounded by a double membrane (inner and outer) , a matrix which is empty space and cristae which are folds created to increase the SA

Question 5

What is the role of the rough endoplasmic reticulum and what is its structure

Answer 5

to fold and process proteins
its a series of interconnected flattened sacs with ribosomes attached to the surface

Question 6

What is the role of the smooth endoplasmic reticulum and what is its structure

Answer 6

to synthesise and process lipids
its a tubular structure with spaces and has no ribosomes attached to its surface

Question 7

What is the role of the golgi apparatus

Answer 7

takes proteins and free ribosomes from the RER , and lipids from the SER to process , modify and package , processed molecules bud off in vesicles which are either used in the cell or exit via exocytosis

Question 8

What is the role of ribosomes

Answer 8

they are the site of protein synthesis and they translate mRNA into amino acids and proteins

Question 9

What is the role of the centrioles

Answer 9

they are important for the accurate separation of chromosomes during cell division and they create spindle fibres

Question 10

What is the role of the lysosomes and what is their structure

Answer 10

they are involved in the breakdown of invading cells and foreign material
they are spherical sacs that contain the digestive enzyme lysozime

Question 11

Plant cells contain the same organelles as animal cells , but what organelles don’t they contain?

Answer 11

centrioles and lysosomes

Question 12

What extra organelles do plant cells contain

Answer 12

chloroplasts
a permanent vacuole
cell wall

Question 13

What is the role of chloroplasts and what is their structure

Answer 13

they use carbon dioxide , oxygen and light energy to build sugars
they are surrounded by a double membrane and the inner one is continuous to increase SA
they contain stacks of thylakoid membranes called grana

Question 14

What are thylakoid membranes the site of …

Answer 14

photosynthesis

Question 15

What is the role of the vacuole and what is the name of its membrane?

What substance does this membrane contain?

Answer 15

its important in keeping the cell firm
it has a membrane called the tonoplast which is filled with cell sap

Question 16

What does cell sap contain

Answer 16

sugars enzymes and pigments within a watery solution

Question 17

What is the role and structure of the cell wall

Answer 17

it provides structure and support to the cell
it is made of cellulose which can act as a carb store
the wall contains pores that can connect 2 cells by their cytoplasm

Question 18

What is cellulose

Answer 18

a polysaccharide

Question 19

What are the pores within the cell wall called and what do they allow

Answer 19

plasmodesmata
they allow the exchange and transport of substances between cells

Question 20

What are prokaryotes

Answer 20

unicellular organisms that have no nucleus and no membrane bound organelles

Question 21

What structures are always present within prokaryotes

Answer 21

a plasma membrane
DNA is contained in the nucleoid
cytoplasm
ribosomes
peptidoglycan cell wall

Question 22

Are ribosomes in prokaryotes bigger or smaller than that of eukaryotes

Answer 22

smaller

Question 23

How do prokaryotic cells reproduce

Answer 23

via binary fission

Question 24

What other structures can be present in prokaryotes

Answer 24

pili
plasmids
capsule
flagella

Question 25

What is the role of pili

Answer 25

they are hair-like structures which attach to other bacterial cells

Question 26

What are plasmids

Answer 26

a circular piece of DNA

Question 27

What is the role of the capsule

Answer 27

it is a protective slimy layer which helps the cell to retain moisture and adhere to surfaces

Question 28

What is the role of flagella

Answer 28

they are tail like structures that are important for locomotion

Question 29

Describe protein transport in cells -include the first 2 points

Answer 29

-proteins are produced on the ribosomes -proteins produced on the surface of the RER are folded and processed in the RER

Question 30

Describe protein transport in cells -include the final 3 points

Answer 30

-proteins are transported from the RER to the Golgi apparatus in vesicles -they are modified in the golgi apparatus -the golgi packages proteins into vesicles so they can be transported to where they are needed in the cell

Question 31

What is the role of microtubules?

Answer 31

they are involved in moving chromosomes from the equator to either poles of the cell during mitosis