c01 cell structure and organisation

Question 1

What is a cell?

Answer 1

A cell is a unit of life which consists of living matter called protoplasm.

Question 2

What is the protoplasm and its parts?

Answer 2

Complex-jelly like substance where many chemical activities that allow the cell to survive and grow take place.
Consists of cell surface membrane, cytoplasm and nucleus.

Question 3

What is the cell surface membrane and its function?

Answer 3

Made up of lipids and proteins.
Function: partially permeable membrane, controls the movement of substances in and out of the cell.

Question 4

What is the cell wall and its function?

Answer 4

Made up of cellulose
Function: protects the cell from injury and gives the cell fixed shape, fully permeable membrane

Question 5

What is the cytoplasm and its function?

Answer 5

Complex-jelly like substance
Function: site where most cell activities occur, contains organelles

Question 6

What is the nucleus and its function?

Answer 6

Surrounded by a nuclear envelope and contains chromatin which is made up of proteins and deoxyribonucleic acid where genes are stored and controls metabolic reactions and synthesises proteins.
Function: controls all cell activities (such as cell growth, repair of worn-out tissues), is essential for cell division

Question 7

What is the rough endoplasmic reticulum and its function?

Answer 7

It is surrounded by a nuclear envelop and surface appears rough due to ribosomes
Function: synthesis proteins to Golgi body for secretion out of the cell

Question 8

What are ribosomes and its function?

Answer 8

Small round structures that are either attached to RER or lies freely in cytoplasm
Function: needed to synthesise proteins for growth in the cell

Question 9

What is the smooth endoplasmic reticulum and its functions?

Answer 9

Tubular shaped and does not have ribosomes attached on its surface
Functions: 1. synthesises lipids and steroids
2. Detoxifies harmful substances

Question 10

What is the Golgi body and its functions?

Answer 10

Disc shaped and stacks of flattened spaces surrounded by membrane
Functions: 1. Chemically modifies substances made by endoplasmic reticulum
2. Stores and packages the substances in vesicles for secretion out of the cell.

Question 11

What are vesicles?

Answer 11

Tiny spherical spaces that can be seen pinching off from one side and fusing with the other

Question 12

What is the mitochondria and its function?

Answer 12

Small oval shaped and has folded inner memrane
Function: site for aerobic respiration where glucose is broken down to release large amounts of energy to be used for active transport, protein synthesis, cell division and transmission of nerve impulses

Question 13

What are chloroplasts and its function?

Answer 13

Oval structures that are only found in plant cells and contains chlorophyll which is a green pigment, move towards higher light intensity
Function: chlorophyll absorbs light energy which is converted to chemical energy and stored as glucose

Question 14

What are vacuoles in plant cells?

Answer 14

Large central vacuole, permanent
Contains cell sap which contains dissolved sugars, mineral salts and amino acids

Question 15

What are vacuoles in animal cells?

Answer 15

Small, round and temporary
Contains water and dissolved substances

Question 16

What is the definition of differentiation?

Answer 16

The process by which a cell becomes specialised for a specific function.

Question 17

What is one adaptation of a red blood cell?

Answer 17

Contains haemoglobin (a red pigment found in the cytoplasm of the RBC).

Question 18

What function does haemoglobin serve in red blood cells?

Answer 18

Binds to oxygen to form oxyhemoglobin and transports oxygen from lungs to tissue cells in the body.

Question 19

What is another adaptation of a red blood cell?

Answer 19

Has a circular biconcave shape.

Question 20

How does the biconcave shape of red blood cells benefit their function?

Answer 20

Increases the surface area to volume ratio so oxygen can diffuse in and out at a faster rate.

Question 21

What is a key adaptation of red blood cells regarding their nucleus?

Answer 21

Lacks a nucleus.

Question 22

What advantage does the lack of a nucleus provide to red blood cells?

Answer 22

Allows the cell to store more haemoglobin for transport of more oxygen.

Question 23

What is an adaptation of red blood cells that affects their flexibility?

Answer 23

Is flexible.

Question 24

Why is the flexibility of red blood cells important?

Answer 24

Can easily squeeze through small lumen in capillaries.

Question 25

What is one adaptation of a muscle cell?

Answer 25

Has many mitochondria.

Question 26

What is the function of mitochondria in muscle cells?

Answer 26

To release large amounts of energy for the muscle cell to contract and relax.

Question 27

What is another adaptation of muscle cells?

Answer 27

Has contractile protein fibres.

Question 28

What is the primary function of muscle cells?

Answer 28

Contracts and relaxes to bring about movement.

Question 29

What is an adaptation of root hair cells?

Answer 29

Long and narrow protrusion.

Question 30

How does the long and narrow protrusion of root hair cells benefit their function?

Answer 30

Increases surface area to volume ratio to absorb water and mineral salts at a faster rate.

Question 31

What is another adaptation of root hair cells?

Answer 31

Large central vacuole.

Question 32

What does the large central vacuole in root hair cells do?

Answer 32

Contains dissolved substances to maintain a lower water potential.

Question 33

How does the lower water potential in root hair cells affect water absorption?

Answer 33

Allows molecules to enter the root hair cell via osmosis.

Question 34

Explain how the sickle cell affects the function of red blood cells.

Answer 34

The sickle cell shape reduces the surface area to volume ratio, decreasing the rate of which oxygen diffuses into and out of the cell so less oxygen is carried to cells. The sickle cell is also not flexible, the sickle cells clump together and block the small lumen in the blood capillaries which decreases the rate of which oxygen is transported to cells.

Question 35

What molecules can pass through Visking tubing?

Answer 35

Water, glucose, maltose (reducing sugars)

Question 36

What are the similarities and differences between Visking tubing and cell surface membrane?

Answer 36

Similarities: Visiking tubing and cell surface membrane are both partially permeable Differences: Visking tubing is a man-made membrane with small pores that only allows small molecules such as water and reducing sugars to pass through, ,maltose (reducing sugar) can pass through while cell surface membrane is a living membrane that only allows some molecules to pass through such as water and glucose and is not simply controlled by small pores in the membrane, maltose cannot pass through