Cell organelles

Question 1

What is the role of the cytoskeleton?

Answer 1

• Holds organelles in place
• Controls cell movement
• Controls movement of organelles

Question 2

What 3 components make up the cytoskeleton?

Answer 2

Microfilaments
Microtubules
Intermediate fibres

Question 3

What are microfilaments formed from?

Answer 3

The protein actin

Question 4

What is the role of microfilaments?

Answer 4

They are contractile fibres which are responsible for:

• cell contraction during cytokinesis
• cell movement

Question 5

What is the role of microtubules?

Answer 5

• Used as a scaffold-like structure that determines the shape of the cell
• Act as tracks for the movement of organelles

Question 6

What is the role of intermediate fibres?

Answer 6

• Give mechanical strength to cells

- Help maintain cell integrity

Question 7

What are centrioles composed of?

Answer 7

Microtubules

Question 8

What are centrioles responsible for?

Answer 8

The assembly and organisation of the spindle fibres during cell division

Question 9

What are flagella and cilia?

Answer 9

Extensions that protrude from some cell types

Question 10

What is the role of flagella?

Answer 10

They enable cells motility

Question 11

What is the smooth endoplasmic reticulum responsible for?

Answer 11

Lipid and carbohydrate synthesis

Storage

Question 12

What is the rough endoplasmic reticulum responsible for?

Answer 12

The synthesis and transport of proteins

Question 13

Where do you find ribosomes?

Answer 13

Either free floating in the cytoplasm, or attached to endoplasmic reticulum (making it rough)

Question 14

Are ribosomes surrounded by a membrane?

Answer 14

No

Question 15

What are ribosomes the site of?

Answer 15

Protein synthesis

Question 16

What is the role of Golgi apparatus?

Answer 16

Modifying proteins and packaging them into vesicles

Question 17

What are the Golgi and endoplasmic reticulum both made up of?

Answer 17

Cisternae

Question 18

Summarise the inter-relationship between organelles in protein production

Answer 18

1) Proteins are synthesised in the ribosomes on the rough endoplasmic reticulum
2) They then pass into the cisternae of the RER, and are packaged into transport vesicles
3) Vesicles containing the protein are moved towards the Golgi via the cytoskeleton
4) The vesicles fuse with the cis face of the Golgi and the proteins enter
5) The proteins are structurally modified before leaving the trans face of the Golgi in vesicles
6) These vesicles are either secretory vesicles, which carry proteins to be released by exocytosis, or lysosomes, which contain proteins for use in the cell

Question 19

What are three structures that plant cells have that animal cells do not?

Answer 19

• Vacuoles (if they appear in animal cells they are small and transient)
• Chloroplasts
• Cell walls

Question 20

What are three general roles of the cytoskeleton?

Answer 20

Providing mechanical strength to cells
Aiding transport within cells
Enabling cell movement

Question 21

What is the structure of chloroplasts?

Answer 21

• Double membrane
• Fluid enclosed
• Internal network of membranes

Question 22

Like mitochondria, what do chloroplasts contain?

Answer 22

Their own DNA and ribosomes

Question 23

Which ribosomes are larger, eukaryotic or prokaryotic?

Answer 23

Eukaryotic ribosomes are 80S (bigger), whereas prokaryotic ribosomes are 70S (smaller)

Question 24

What are plant cell walls made out of?

Answer 24

Cellulose

Question 25

What are prokaryotic cell walls made out of?

Answer 25

Peptidoglycan

Question 26

3 similarities between prokaryotic and eukaryotic cells

Answer 26

Both contain ribosomes
Both have a cytoskeleton
Both have a cell-surface membrane

Question 27

3 differences between prokaryotic and eukaryotic cells

Answer 27

Prokaryotic do not have a nucleus
Prokaryotic have no membrane-bound organelles
Prokaryotic have a peptidoglycan cell wall

Question 28

What are fungi cell walls made out of?

Answer 28

Chitin