1 CELLS, BIOLOGICAL MOLECULES, ENZYMES + KINGDOMS

Question 1

Role of nucleus

Answer 1

Controls activity of cell by making proteins, and contains chromosomes

Question 2

Role of cell membrane

Answer 2

Controls what enters and leaves the cell (selectively permeable)

Question 3

Role of cytoplasm

Answer 3

Chemical reactions occur

Question 4

Role of mitochondria

Answer 4

Carried out aerobic respiration

Question 5

Role of ribosomes

Answer 5

Synthesise proteins from amino acids

Question 6

Role of chloroplasts

Answer 6

Carry out photosynthesis

Question 7

Role of cell wall

Answer 7

Keeps cells fixed in shape (made of cellulose)

Question 8

Role of vacuole

Answer 8

Watery sap that stores dissolved sugars, mineral ions and other substances

Question 9

What organelles are in a plant cell

Answer 9

Cytoplasm, chloroplast, nucleus, ribosomes, mitochondria, cell wall, cell membrane, vacuole

Question 10

What organelles are in an animal cell

Answer 10

Cell membrane, mitochondria, ribosomes, cytoplasm, nucleus

Question 11

Chemical composition of carbohydrates

Answer 11

Carbon, hydrogen and oxygen

Question 12

Storage carbohydrate in plants

Answer 12

Starch

Question 13

Storage carbohydrate in animals and fungi

Answer 13

Glycogen

Question 14

Why are starch and glycogen better storage molecules than simple sugars

Answer 14

Less soluble, so have less effect on water movement in and out of the cells

Question 15

Chemical composition of lipids

Answer 15

Carbon, hydrogen and oxygen

Question 16

Structure of a fat cell

Answer 16

Glycerol backbone with 3 fatty acids

Question 17

Structure of a carbohydrate

Answer 17

Lots of simple sugars like glucose

Question 18

Chemical composition of proteins

Answer 18

Carbon, hydrogen, oxygen and nitrogen

Question 19

Structure of a protein

Answer 19

A variation of 20 amino-acids in any order

Question 20

Describe the test for reducing sugars (glucose)

Answer 20

• Add benedict’s solution to a samle of food in solution
• Place in water bath at 80c for 5mins
• Blue to brick red
• Green, yellow and orange are positive, but in low concentration

Question 21

Test for starch

Answer 21

• Add few drops of orange iodine solution to a sample on a spotting tile
• A blue-black colour indicates starch

Question 22

Test for protein

Answer 22

• Add water to sample to form solution
• Add equal volume of potassium hydroxide and shake
• Add two drops of 1% copper sulfate solution
• A pale purple colour will develop

Question 23

Test for lipids

Answer 23

• Add small volume of absolute ethanol and shake
• Add equal volume water
• A cloudy white colour will form

Question 24

Define a catalyst

Answer 24

A chemical that increases the rate of reaction, without being used up in the reaction itself

Question 25

Describe how an enzyme works

Answer 25

* Substate and enzyme collide * Substrate binds to active site of enzyme * The reaction occuring means the products no longer fit the active sites shape and so are released * The enzyme is free to catalyse the next reaction

Question 26

How does an increase in temperature affect the rate of an enzyme controlled reaction

Answer 26

* As temperature increases, the rate increases until an optimum temperature has been reached * Gives enzymes and substrates more kinetic energy * Move faster and collide more often * Too hot, and enzyme denatures, and active site changes shape * Substate cannot bind to active site and reason cannot occur

Question 27

How does too high/low pH affect the rate of an ezyme controlled reaction

Answer 27

* pH change changes shape of enzyme * Become permenantly denaturesd * Active site changes shape, so substrate is no longer complementary to the substrate and reaction cannot occur

Question 28

What characteristics do all living organisms share

Answer 28

* Move * Respire * Respond to surroundings * Homeostatis * Grow * Reproduce * Excrete * Nutrition

Question 29

Cell wall of plant

Answer 29

Cellulose

Question 30

Carbohydrate storage of a plant cell

Answer 30

Starch

Question 31

Carbohydrate storage of an animal cell

Answer 31

Glycogen

Question 32

Organisation of a fungi

Answer 32

Thread like hyphae make up a mycelium

Question 33

Cell wall of fungi

Answer 33

Chitin

Question 34

How do fungi feed

Answer 34

Saprotrophic nutrition

Question 35

Carbohydrate storage of fungi

Answer 35

Glycogen

Question 36

Pathogenic protoctista

Answer 36

Plasmodium

Question 37

What kingdoms can be pathogens

Answer 37

Fungi, bacteria, protoctista or virus

Question 38

Describe the levels of organisation in organisms

Answer 38

* Organelles * Cells * Tissues * Organs * Organ systems

Question 39

Name a pathogenic protoctist and what disease it causes

Answer 39

Plasmodium causes malaria

Question 40

Describe how an enzyme works

Answer 40

* Substate and enzyme collide * Substrate binds to active site of enzyme * The reaction occuring means the products no longer fit the active sites shape and so are released * The enzyme is free to catalyse the next reaction