2.1 Cell Structure

Question 1

What are plasmodesmata?

Answer 1

Channels/holes in a plant cell walls to allow exchange with adjacent cells

Question 2

What are plant cell walls made of?

Answer 2

Cellulose (β-glucose polymer)

Question 3

What are fungi cell walls made of?

Answer 3

Chitin (polysaccharide)

Question 4

What are bacteria cell walls made of?

Answer 4

Murein (glycoprotein polymer)

Question 5

Differences between plant and animal cells

Answer 5

• Plasmodemata
• Chloroplast
• Vacuole
• Cell wall

Question 6

Nucleoulus funtion

Answer 6

Production of ribosomes

Question 7

What are ribosomes made of?

Answer 7

rRNA and proteins - 80s and 70s have different protein subunits

Question 8

Nucleus structure

Answer 8

Nuclear envelope with many nuclear pores surrounding chromosomes and nucleoli

Question 9

Nucleus function

Answer 9

• House DNA
• Site of transcription of DNA into mRNA to produce proteins
• House nucleoli

Question 10

Mitochondria structure

Answer 10

Oval shaped, double membrane, inner membrane folded to form cristae, matrix inside with enzymes, ribosomes and genetic information

Question 11

Golgi apparatus structure

Answer 11

Groups of fluid filled, membrane bound flattened sacs

Question 12

Golgi apparatus function

Answer 12

• Process and package new lipids and proteins

- Produce lysosomes

Question 13

RER structure

Answer 13

System of fluid filled space, membrane bound and covered with ribosomes

Question 14

RER function

Answer 14

Folds and process proteins produced at attached ribosomes

Question 15

SER structure

Answer 15

System of fluid filled space, membrane bound

Question 16

SER function

Answer 16

Synthesise and process lipids

Question 17

Lysozyme structure

Answer 17

Round, membrane bound, no clear internal structures, filled with lysozymes

Question 18

Cell vacuole structure

Answer 18

Tonoplast membrane surrounding cell sap

- Cell sap = soln of sugar and salts

Question 19

3 functions of cell vacuole

Answer 19

• Maintain pressure in cell ∴ rigidity
• Prevents cell wilting
• Isolates unwanted chemicals in cell

Question 20

Chloroplast structure

Answer 20

Flattened structure, double membrane, thick stroma, thylakoid membranes inside, thylakoids stacked into grana which are linked with lamellae (thin flat membrane extensions)

Question 21

Which types of cell photosynthesise?

Answer 21

Plant cells + algae

Question 22

Eukaryote DNA description

Answer 22

Linear-DNA which is histone/protein bound

Question 23

Prokaryote DNA description

Answer 23

Circular DNA in one long coiled strand not protein associated

Question 24

3 prokaryote only features

Answer 24

• Plasmids (multiple?/0) (short loops of DNA not a part of main circular DNA molecule)
• Flagella (multiple?/0)
• Capsule made of secreted slime

Question 25

Virus structure

Answer 25

No plasma membrane, no cytoplasm, no ribosomes

Core genetic material surrounded by protein coat/capsid with attachment proteins

Question 26

Binary fission in prokaryotes steps (4)

Answer 26

1) Circular DNA strand and plasmids replicate
2) Cell gets bigger and the 2 circular DNA strands move to opposite poles of cell
3) Cytoplasm divides and new cell wall forms
4) 2 daughter cells with identical circular DNA formed and variable plasmid numbers

Question 27

Virus replication

Answer 27

1) Virus attaches to host cell using attachment proteins complementary to receptor proteins
2) Virus injects core genetic material into host cell which replicates viral particles