Topic B1

Question 1

Prokaryotic cells

Answer 1

Do not contain a nucleus, bacterial cell

Question 2

Eukaryotic cells

Answer 2

Have a nucleus, animal+plant

Question 3

Parts of an animal cell

Answer 3

1. Nucleus-contains DNA
2. Mitochondria-where most respiration happens
   3.Cytoplasm-where most of the chemical reactions happen
   4.Ribosomes-where are proteins are made
   5.Cell membrane-controls what goes in and out

Question 4

Parts of a plant cell

Answer 4

Same sub cellular structures as an animal cell plus
1.Cell walls-made of cellulose, strengthens the cell
2.Vacuole-contains cell sap
3.Chloroplast-where photosynthesis occurs

Question 5

Parts of a bacterial cell

Answer 5

1.Cell membrane
2.Ribosome
3.Plasmid DNA-loop of extra DNA
4.Chromosomal DNA-contain cells activities
5.Flagellum-for movement

Question 6

Egg cell

Answer 6

Carries female DNA and feeds developing embryo

Question 7

Specialised cell

Answer 7

Cell that has a structure adapted to function

Question 8

Parts of an egg cell

Answer 8

-Nutrients in cytoplasm
-Haploid nucleus
-Cell membrane, changes the structure of fertilisation to prevent more sperm entering

Question 9

Sperm cell

Answer 9

Transport male DNA to egg

Question 10

Parts of a sperm cell

Answer 10

-Haploid nucleus
-Tail for swimming to egg
-Lots of mitochondria to provide energy for swimming
-Acrosome contains enzymes for digesting egg membrane

Question 11

Ciliated epithelial cell

Answer 11

Move substances along internal surfaces e.g. mucus in airways
-cilia ‘beat’ to move substances 

Question 12

Enzymes

Answer 12

Catalyse chemical reactions

Question 13

Why can enzymes only catalyse one specific reaction?

Answer 13

Because of the unique shape of its active site

Question 14

Factors that affect enzyme activity 

Answer 14

-High temperatures and high and low pH denature enzymes, change the shape of the active site so enzyme no longer works
-More substrate molecules means enzyme and substrate are more likely to meet

Question 15

Enzymes in organisms

Answer 15

Break big molecules in smaller ones

Question 16

Carbohydrase

Answer 16

Turn carbohydrates e.g. starch into sugars

Question 17

Protease

Answer 17

Turn proteins into amino acids

Question 18

Lipases

Answer 18

Turn lipids into glycerol and fatty acids

Question 19

Diffusion

Answer 19

Spreading out of particles from high to low concentration

Question 20

Active transport

Answer 20

Favourite of particles against concentration gradient

Question 21

Osmosis

Answer 21

Movement of water molecules across a partially permeable membrane from high to low concentration