cells

Question 1

all cells have what?

Answer 1

a cell membrane

Question 2

cell membranes surround what?

Answer 2

the cytoplasm

Question 3

plant cells contain what 3 things that animal cells dont?

Answer 3

• chloroplasts
• vacuole
• cell wall

Question 4

function of the nucleus?

Answer 4

• controls the activity in the cell
• contains the chromosomes

Question 5

function of the cell membrane?

Answer 5

• selectively permeable- controls what substances enter and leave the cell

Question 6

function of the cytoplasm?

Answer 6

• jelly-like liquid where chemical reactions occur

Question 7

function of the mitochondria?

Answer 7

• carries out some reactions of aerobic respiration, producing ATP

Question 8

function of ribosomes?

Answer 8

• site of protein synthesis

Question 9

function of chloroplasts?

Answer 9

• absorb light energy and use it for photosynthesis, making biological molecules for plant cells

Question 10

function of the cell wall?

Answer 10

• made of cellulose
• helps to keep plant cells in a fixed shape and keeps the plant upright

Question 11

function of the vacuole?

Answer 11

• filled with cell sap
• stores dissolved sugars, mineral ions and other substances

Question 12

what are organelles?

Answer 12

structures that carry out specific processes the cells need to survive

Question 13

what are tissues?

Answer 13

groups of similar cells which work together to carry out the same function

Question 14

what are organs?

Answer 14

made up of several different tissues working together to carry out a more complex function

Question 15

what are organ systems?

Answer 15

made up of several different organs working together to carry out a complex function essential to life

Question 16

what are specialised cells?

Answer 16

cells that have the structures and proteins needed to carry out a specific job in the organism

Question 17

what is the function of red blood cells?

Answer 17

to transport oxygen in the blood

Question 18

what are features of a red blood cell?

Answer 18

• contains the protein haemoglobin- binds to and transports oxygen
• no nucleus- more space for haemoglobin
• biconcave shape- larger SA so oxygen can enter and leave the cell more rapidly

Question 19

what is the function of sperm cells?

Answer 19

to transport male genetic material to the egg cell

Question 20

what are features of a sperm cell?

Answer 20

• flagellum to help it swim
• contains many mitochondria to provide energy for swimming
• 1/2 genetic DNA

Question 21

what is the function of a palisade cell?

Answer 21

to carry out photosynthesis

Question 22

what are the features of a palisade cell?

Answer 22

• many chloroplasts- trap light energy for photosynthesis
• tall & thin- cells can pack tightly together so more of the light reaching the leaf is absorbed

Question 23

what are carbohydrates made of?

Answer 23

carbon, hydrogen and oxygen

Question 24

what are carbohydrates used for?

Answer 24

• broken down in respiration to release ATP

Question 25

what are the smallest units of carbohydrates?

Answer 25

simple sugars (e.g. glucose and fructose)

Question 26

what makes sucrose?

Answer 26

glucose + fructose

Question 27

what is starch used for?

Answer 27

used to store glucose in plants

Question 28

what is glycogen used for?

Answer 28

used to store glucose in animals and fungi

Question 29

why are starch and glycogen better storage molecules?

Answer 29

they are less soluble than simple sugars and so they have less effect on water movement in and out of cells

Question 30

what are fats made out of?

Answer 30

carbon, hydrogen and oxygen

Question 31

fats are what type of acid joined to what molecule?

Answer 31

3 fatty acids joined to a glycerol molecule

Question 32

what are the functions of fats?

Answer 32

- energy storage - thermal insulation - buoyancy

Question 33

what are proteins made of?

Answer 33

carbon, hydrogen, oxygen and nitrogen

Question 34

proteins are made of many ...

Answer 34

amino acids joined together

Question 35

functions of proteins?

Answer 35

- combating diseases- antibodies - transport e.g. haemoglobin and cell membrane proteins

Question 36

what is an enzyme?

Answer 36

biological catalysts

Question 37

what is a catalyst?

Answer 37

a chemical that increases the rate of reaction without being used up in the reaction

Question 38

what is the lock & key theory?

Answer 38

1) the substrate and enzyme collide 2) the substrate binds to the active site of the enzyme 3) once the reaction has occurred, the products dont fit the active site's shape