cell structure

Question 1

what are the organelles in an animal cell?

Answer 1

• plasma (cell surface) membrane
• rough endoplasmic reticulum
• nucleolus
• nucleus
• smooth endoplasmic reticulum
• lysosomes
• ribosomes
• nuclear envelope
• golgi apparatus
• cytoplasm
• mitochondrion

Question 2

what are the organelles in a plant cell?

Answer 2

• plasma (cell surface) membrane
• chloroplasts
• rough endoplasmic reticulum
• nucleolus
• nucleus
• smooth endoplasmic reticulum
• plasmodesmata
• vacuole
• ribosomes
• nuclear envelope
• golgi apparatus
• cytoplasm
• mitochondrion
• cell wall

Question 3

what is the description and function of a plasma membrane?

Answer 3

• membrane mainly made of lipids and proteins.

• it regulates the movement of substances in and out of the cell.
• also has receptor molecules which allow it to respond to chemicals like hormones (cell signalling).

Question 4

what is the description and function of a cell wall?

Answer 4

• a rigid structure that surrounds plant cells mainly made of cellulose (the carbohydrate).

• supports plant cells

Question 5

what is the description and function of a nucleus?

Answer 5

• a large organelle surrounded by a nuclear envelope which contains many pores. contains chromatin and the nucleolus.

• controls the cell’s activities (by controlling transcription of DNA).
• pores allow substances (like RNA) to move between the nucleus and cytoplasm.
• nucleolus makes ribosomes.

Question 6

what is the description and function of a lysosome?

Answer 6

• round organelle surrounded by a membrane with no clear internal structure.

• contains digestive enzymes which are kept separate from surrounding cytoplasm by its membrane.
• can be used to digest invading cells or break down cellular waste matter.

Question 7

what is the description and function of a ribosome?

Answer 7

• a very small organelle that floats free in cytoplasm or is attached to RER. made up of proteins and RNA. not surrounded by membrane.

• the site where proteins are made.

Question 8

what is the description and function of the rough endoplasmic reticulum?

Answer 8

• a system of membranes enclosing a fluid-filled space. the surface is covered with ribosomes.

• folds and processes proteins that have been made at the ribosomes.

Question 9

what is the description and function of the smooth endoplasmic reticulum?

Answer 9

• similar to rough endoplasmic reticulum, but with no ribosomes.

• synthesises and processes lipids.

Question 10

what is the description and function of a vesicle?

Answer 10

• a small, fluid-filled sac in the cytoplasm, surrounded by a membrane.

• transports substances in and out of the cell (via plasma membrane) and between organelles.
• some are formed by golgi apparatus while others are formed at cell surface.

Question 11

what is the description and function of the golgi apparatus?

Answer 11

• a group of fluid-filled, membrane-bound, flattened sacs. vesicles are often seen at the edges of the sacs.

• it processes and packages new lipids and proteins.
• also makes lysosomes

Question 12

what is the description and function of the mitochondria?

Answer 12

• usually oval-shaped. have a double membrane (inner one is folded to form structures called cristae.
• inside is the matrix which contains enzymes involved in respiration.

• site of aerobic respiration, where ATP is produced.
• found in large numbers in cells that are very active and require a lot of energy.