Biology- Cell Structure

Question 1

Give 13 organelles in eukaryotic cells

Answer 1

1. Cell surface membrane
2. Nucleus
3. Mitochondria
4. Chloroplasts
5. Golgi Apparatus
6. Golgi vesicles
7. Lysosomes
8. Ribosomes
9. Rough endoplasmic reticulum
10. Smooth endoplasmic reticulum
11. Cell wall
12. Cell vacuole
13. Cytoplasm

Question 2

Give 4 parts of the nucleus

Answer 2

Nuclear pore
Nuclear envelope
Nucleolus
Nucleolus

Question 3

Outline the structure of the nucleus (5)

Answer 3

Nuclear envelope (double membrane)

Nuclear pores

Nucleoplasm - granular, jelly-like substance

Chromosomes - protein-bound, linear DNA

Nucleolus - smaller sphere inside which is the site of rRNA production and also makes ribosomes.

Question 4

Outline the function of the nucleus (2)

Answer 4

The site of DNA replication and the site of transcription ( making mRNA)

Contains the genetic code for each cell

Question 5

Outline the structure of the endoplasmic reticulum (2)

Answer 5

Rough and smooth endoplasmic reticulum both are made up of flattened membrane sacks called cisternae

Rough endoplasmic reticulum have ribosomes on the cisternae.

Question 6

What’s the function of the RER (rough endoplasmic reticulum)

Answer 6

Protein synthesis (on the ribosomes)

Question 7

What’s the function of the RER (rough endoplasmic reticulum)

Answer 7

Protein synthesis

Question 8

What’s the function of the SER (smooth endoplasmic reticulum)

Answer 8

Synthesis and storage of lipids and carbohydrates

Question 9

Outline the structure of the golgi apparatus and vesicles 2)

Answer 9

Folded membranes making cisternae

Secretary vesicles pinch off from the cisternae, to transport things around the cell

Question 10

Outline the function of the golgi apparatus and vesicles (7)

Answer 10

1) golgi apparatus adds carbohydrates to proteins to form glycoproteins

2) produces secretory enzymes

3) secretes carbohydrates

4) transports and modifies proteins, carbohydrates and lipids, as well as storing lipids.

5) forms Lysosomes (vesicles that contain the enzymes)

6) ‘labels’ molecules for their destination, e.g. adding a receptor

7) the finished products are transported to the cell surface membrane in Golgi vesicles where they fuse with the membrane and the contents are released.

Question 11

Outline the structure of Lysosomes (1)

Answer 11

Membrane -bound bags of digestive enzymes

Question 12

Outline the function of Lysosomes (4)

Answer 12

1) hydrolyse phagocytic cells

2) completely break down dead cells (autolysis)

3) exocytosis - release enzymes to outside of cell to destroy material

4) digest worn out organelles for reuse of materials

Question 13

Outline the function of Lysosomes (4)

Answer 13

1) hydrolyse phagocytic cells

2) completely break down dead cells (autolysis)

3) exocytosis - release enzymes to outside of cell to destroy material

4) digest worn out organelles for reuse of materials

Question 14

Outline the structure of mitochondria (4)

Answer 14

1) double membrane

2) inner membrane is folded to make cristae

3) the fluid centre is called the mitochondrial matrix

4) has it’s own loops of DNA

Question 15

Outline the function of mitochondria (3)

Answer 15

1) site of aerobic respiration

2) site of ATP production

3) contains it’s own DNA to code for enzymes needed in respiration

Question 16

Outline the structure of ribosomes (2)

Answer 16

1) made up of 2 sub units of protein and and rRNA.

2) There are 2 types of ribosomes depending on if they are found in a eukaryotic cell or prokaryotic cell:

Eukaryotic cells - large ribosomes (called 80s)

Prokaryotic cells - smaller ribosomes (called 70s)

Question 17

Outline the function of a ribosome (1)

Answer 17

The site of Protein synthesis

Question 18

Outline the function of a ribosome (1)

Answer 18

Protein synthesis

Question 19

Outline the structure of vacuoles (2)

Answer 19

Filled with fluid

Surrounded by a single membrane called the tonoplast

Question 20

Outline the structure of vacuoles (2)

Answer 20

Filled with fluid

Surrounded by a single membrane called the tonoplast

Question 21

Outline the functions of the vacuole (3)

Answer 21

1) they make plant cells turgid and therefore provide support

2) temporary store of sugars and amino acids

3) the pigment may sometimes colour petals to attract pollinators

Question 22

Outline the structure of chloroplasts (4)

Answer 22

1) surrounded by a double membrane

2) contains thylakoid membranes (folded membranes embedded with the chlorophyll pigment) that can stack up to make a granum

3) the fluid-filled stroma contains enzymes required for photosynthesis

4) they have their own DNA

Question 23

Outline the function of chloroplasts

Answer 23

This is the site of photosynthesis

Question 24

Outline the structure of the cell wall

Answer 24

1) found in plant and fungi cells:

Plants- made of microfibrils if the cellulose polymer

Fungi - made of chitin, a nitrogen - containing polysaccharide

Question 25

Outline the function of the cell wall (1)

Answer 25

Provides structural strength to the cell

Question 26

Outline the structure of the plasma membrane (2)

Answer 26

1) phospholipid bilayer 2) has molecules embedded onto it from both the inside and the outside ( proteins, carbohydrates, cholesterol etc)

Question 27

Outline the function of the plasma membrane

Answer 27

Controls what leaves and enters the cell