2.1.5- Other Features Of Eukaryotic Cells

Question 1

What are ribosomes made of?

Answer 1

Ribosomal RNA.

Question 2

Where are ribosomes made?

Answer 2

Nucleolus.

Question 3

Explain how ribosomes are made.

Answer 3

They’re made in the nucleolus as two separate subunits and pass through the nuclear envelope to the cell cytoplasm which is where they combine.

Question 4

After ribosomes are made, what are the two places they can go to within the cell?

Answer 4

They can either remain free in the cytoplasm or attach to the rough endoplasmic reticulum (RER).

Question 5

In eukaryotes, ribosomes are _______ and _______ organelles.

Answer 5

small and spherical.

Question 6

In eukaryotic cells, what size are the ribosomes?

Answer 6

About 20nm in diameter.

Question 7

What is the function of ribosomes that are bound to the exterior of the rough endoplasmic reticulum?

Answer 7

They synthesise proteins that will be exported out of the cell.

Question 8

What’s the function of ribosomes free in the cell cytoplasm?

Answer 8

They assemble proteins that will be used inside the cell.

Question 9

What are the two ways ribosomes free in the cell cytoplasm can exist?

Answer 9

Singular or in clusters of ribosomes.

Question 10

What are the four non membrane bound organelles that are going in a eukaryotic cell?

Answer 10

Ribosomes
centrioles
Cytoskeleton
Cellulose cell wall

Question 11

Explain what the structure of centrioles is.

Answer 11

They consist of two bundles of microtubules at right angles to each other. The microtubules are made of tubulin protein subunits that are arranged to form a cylinder.

Question 12

The microtubules in centrioles and the cytoskeleton are made of…

Answer 12

Tubulin subunits.

Question 13

What are the two main functions of centrioles?

Answer 13

• involved in cell division.

* involved in the formation of cilia and undulipodia.

Question 14

Explain how centrioles are involved in cell division.

Answer 14

Before cell division, the spindle (made of tubulin threads) forms from centrioles and chromosomes attach to the middle part of the spindle and motor proteins walk along the tubulin threads to pull the chromosomes to opposite ends of the cell.

Question 15

Explain how centrioles are involved in the formation of cilia and undulipodia.

Answer 15

Before the cilia form, the centrioles line up and multiple underneath the cell surface membrane. The microtubules sprout outwards from each centrioles to form a cillium or undulipodium.

Question 16

In what type of plants are centrioles found or not found?

Answer 16

They’re usually absent from cells of higher plants- but are present in some unicellular green algae- e.g; Chlamydomonas.

Question 17

Where is the plant cell wall located in relation to the plasma membrane?

Answer 17

It is usually on the outside of the plasma membrane.

Question 18

The plant cell wall is made from bundles of ______ fibres.

Answer 18

Cellulose.

Question 19

The cellulose cell wall is strong and can help cells from doing what when they’re turgid.

Answer 19

Bursting.

Question 20

Fungi that have cell walls have walls that are made of _______ and not cellulose.

Answer 20

Chitin.

Question 21

List the four main functions of the cellulose cell wall in plant cells.

Answer 21

• maintain cell shape
• provide strength and support
• contribute to the strength and support of the whole plant
• are permeable and allow solutions (solute and solvent) to pass through

Question 22

What are the four main things the cytoskeleton consists of?

Answer 22

Micro filaments
Intermediate filaments
Microtubules
Cytoskeletal motor proteins

Question 23

The rod like microfilaments in the cytoskeleton are made of what?

Answer 23

Subunits of the protein actin.

Question 24

The microfilaments in the cytoskeleton are __________ of the protein actin.

Answer 24

Polymers.

Question 25

How large is each of the microfilaments present in the cytoskeleton?

Answer 25

Each microfilament is about 7nm in diameter.

Question 26

The intermediate filaments present in the cytoskeleton are ______ in diameter about.

Answer 26

10nm- intermediate filaments.

Question 27

The microtubules in the cytoskeleton are ________ and _________.

Answer 27

Straight and cylindrical.

Question 28

What size are the microtubules present in the cytoskeleton on average?

Answer 28

18-30nm in diameter.

Question 29

What are the three types of cytoskeletal motor proteins?

Answer 29

Mysoins Kinesins Dyneins

Question 30

The cytoskeleton motor proteins are described as __________ _________.

Answer 30

Molecular motors.

Question 31

As well as being molecular motors, explain what else the cytoskeletal motor proteins do.

Answer 31

They are also enzymes that have a site that binds to and allies the hydrolysis of ATP as their energy source.

Question 32

What are the three functions of the protein microfilaments within the cytoplasm.

Answer 32

* give support and mechanical strength. * keep the cells shape stable. * allow cell movement.

Question 33

What are the two main functions of the microtubules that are present in the cytoskeleton?

Answer 33

* provide shape and support to cells | * help substances and organelles to move through the cytoplasm within a cell

Question 34

Describe three ways in which the cytoskeletal microtubules can help substances and organelles to move within the cell through the cell cytoplasm.

Answer 34

* they make up the cilia and undulipodia * form a spindle before a cell divides that allow chromosomes to be moved within the cell * form the train along which motor proteins walk and drag organelles from one part of the cell to another.

Question 35

Explain all of the functions of the intermediate functions that are present in the cytoskeleton.

Answer 35

* anchor the nucleus within the cytoplasm. * extend between cells in come tissues, between special junctions to enable cell- cell signalling and allowing cells to adhere to the basement membrane to stabilise the tissues.

Question 36

_________ calls do my have a cellulose cell wall

Answer 36

Animal

Question 36

Explain how motor proteins get energy that is vital for them to use inside the cell.

Answer 36

They have a site that binds to and allows the hydrolysis of ATP as their energy source.