Animal Cells

Question 1

What is an “Organelle”?

Answer 1

A specialised structure found within a living cell.

Question 2

Describe the structure and state the function of the “Plasma Membrane”

Answer 2

• Composed of phospholipid bilayer, with proteins embedded in the layer
• is selectively permeable, regulates the transport of materials into and out of the cell. Separates cell contents from the outside environment.

Question 3

Describe the structure and state the function of the “Cytoplasm”

Answer 3

• Cytoplasm is a thick, gelatinous, semi-transparent fluid

- Maintains cell shape and stores chemicals needed by the cell for metabolic reactions.

Question 4

Describe the structure and state the function of the “Nucleus”

Answer 4

• The largest organelle, surrounded by a nuclear envelope. Envelopes has nuclear pores which allow movement of molecules through it. It also contains chromatin
• Controls cellular activity and houses genetic material called chromatin, DNA and proteins, rom which comes the instructions for making proteins.

Question 5

Describe the structure and state the function of the “Nucleolus”

Answer 5

• Dense spherical structure in the middle of the nucleus

- Makes RNA and ribosomes.

Question 6

Describe the structure and state the function of the “Rough endoplasmic reticulum (ER)”

Answer 6

• Membrane bound flattened sacs called cisternae studded with ribosomes
• Protein synthesis takes place on the ribosomes and the newly synthesised proteins are transported to the Golgi apparatus.

Question 7

Describe the structure and state the function of the “Smooth endoplasmic reticulum (ER)”

Answer 7

• membrane bound flattened sacs called cisternae with no ribosomes (not studded)
• Responsible for synthesis and transport of lipids and carbohydrates.

Question 8

Describe the structure and state the function of the “Golgi Apparatus”

Answer 8

• A stack of membrane bound flattened sacs.
• Newly made proteins are received here from the rough ER. The Golgi apparatus modifies them and then packages the proteins into vesicles to be transported to where they are needed.

Question 9

Describe the structure and state the function of the “Vesicles”

Answer 9

• Small spherical membrane bound sacs with fluid inside
• Transport vesicle are used to transport materials inside the cell and secretory vesicles transport proteins that are to be released from the cell, to the cell surface membrane.

Question 10

Describe the structure and state the function of the “Lysosomes”

Answer 10

• Small spherical membrane bound sacs containing hydrolytic enzymes
• They break down waste material including old organelles.

Question 11

Describe the structure and state the function of the “Ribosomes”

Answer 11

• Tiny organelles attached to rough ER or free floating in the cell. They consist of two sub-units and they are not surrounded by a membrane
• Protein synthesis occurs at the ribosomes.

Question 12

Describe the structure and state the function of the “Mitochondria”

Answer 12

• Have two membranes. Inner membrane, highly folded to form cristae. The central part is called the matrix. They can be seen as long in shape or spherical depending on which angle the cell is cut at.
• They are the site of the final stages of cellular respiration.

Question 13

Describe the structure and state the function of the “Centrioles”

Answer 13

• They are small tubes of protein fibres

- They form spindle fibres during cell division

Question 14

What is meant by “Exocytosis”?

Answer 14

The process of vesicles fusing with plasma membrane and secreting contents.