3.2.1: Structure of cells

Question 1

Strcuture of nucleus? (4)

Answer 1

1) Nuclear envelope - double membrane

2) Nuclear pores

3) Chromosomes - Linear DNA

4) Nucleolus - Site of rRNA production and makes ribosomes

Question 2

Function of nucleus (2)

Answer 2

1) Site of DNA replication and transcription

2) Contains genetic code for each cell

Question 3

Structure of rough endoplasmic reticulum (2)

Answer 3

• Folded membrane called cisternae
• Ribosomes

Question 4

Function of rough endoplasmic reticulum (1)

Answer 4

1) Protein synthesis

Question 5

Structure of smooth endoplasmic reticulum (1)

Answer 5

1) Folded membranes called cisternae

Question 6

Function of SER (1)

Answer 6

1) Synthesis and store lipids and carbohydrates

Question 7

Structure of Golgi body (2)

Answer 7

1) Folded membrane called cisternae

2) Secretary vesicles pinch off from cisternae

Question 8

Function of Golgi body (6)

Answer 8

1) Add carbohydrates to proteins to form glycoproteins

2) Produce secretary enzymes

3) Secretes carbohydrates

4) Transport, modify and stores lipids

5) Form lysosomes

6) Finished produced are transported to cell surface in vesicles where they fuse with the membrane and the contents released

Question 9

Structure of lysosomes (1)

Answer 9

1) Contains hydrolytic enzymes

Question 10

Function of lysosomes (4)

Answer 10

1) Hydrolyse phagocytic cells

2) Break down dead cells

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

4) Digest worn out organelles for reuse of materials

Question 11

Structure of mitochondria (4)

Answer 11

1) Double membrane

2) Inner membrane called cristae

3) Fluid centre called the mitochondrial matrix

4) Loop of mitochondrial DNA

Question 12

Function of mitochondria (3)

Answer 12

1) Site of aerobic respiration

2) Site of ATP production

3) DNA to code for enzymes needed in respiration

Question 13

Structure of ribosomes (3)

Answer 13

1) Made up of two sub unites of protein and rRNA

2) 80s - large ribosomes found in eukaryotic cells

3) 70s - smaller ribosomes found in prokaryotic cells, mitochondria and ribosomes

Question 14

Function of ribosomes (1)

Answer 14

Site of protein synthesis

Question 15

Structure of vacuole (1)

Answer 15

Filled with fluid surrounded by a single membrane called a tonoplast

Question 16

Function of vacuole (2)

Answer 16

1) Makes cell turgid and provide support

2) Temporary stores of sugars and amino acids

Question 17

Structure and function of chloroplast (5)

Answer 17

1) Granum - stack of thylakoid membrane

2) Thylakoid membrane - contains chlorophyll for photosynthesis and ATP synthase to produce ATP

3) Stroma - fluid filled

4) Starch grains - Energy storage molecule in plants

5) DNA and ribosomes - own DNA and 70s ribosomes for synthesis of enzymes for photosynthesis

Question 18

Structure of cell wall (2)

Answer 18

1) Plants - made of microfibrils of the cellulose polymer

2) Fungi - made of chitin

Question 19

Function of cell wall (1)

Answer 19

Provides structural strength

Question 20

Structure of cell surface membrane (1)

Answer 20

1) Phospholipid bilayer - Made up of phospholipids, specific transport proteins and carbohydrates arranged in a fluid mosaic model

Question 21

Function of membrane (1)

Answer 21

Controls entrance and exit of molecules