Cell structure methodology exam paper

Question 1

how could scientist use temporary mounts of leaves to determine the mean number of chloroplast in mesophyll cells?

Answer 1

1) select a large number of cells
2) Count the number of chloroplast
3) divide the number of chloroplast by the number of cells

Question 2

name two structures in a eukaryotic cell that cannot be identified using a light microscope

Answer 2

1) mitochondria

2) ribosomes

Question 3

explain one difference in structure of starch molecules and Celulose molecules

Answer 3

1) starch is formed by alpha glucose molecules whereas cellulose is formed from beta glucose molecules
2) The position of the hydroxyl group on carbon atom 1 is inverted (cellulose)

Question 4

explain one way in which starch molecules are adapted for their function in plant cells

Answer 4

Starch molecules are insoluble this means water potential is affected via osmosis and it doesn’t dissolve

Question 5

Explain how cellulose molecules are adapted for their function in plant cells

Answer 5

they have hydrogen that links the long chains of beta glucose molecules in order to strengthen the structure this helps maintain the shape of the cell wall by keeping it turgid

Question 6

how do you know when a transmission electron microscope is used to produce an image

Answer 6

1) high resolution

2) you can see internal structures e.g mitochondria

Question 7

what is the function of the rough endoplasmic reticulum

Answer 7

Protein synthesis

Question 8

what is the function of the Golgi apparatus

Answer 8

to modify proteins

Question 9

What is the function of mitochondria

Answer 9

Aerobic respiration

Question 10

describe the arrangement of phospholipids in plasma membrane

Answer 10

1) Hydro phobic phosphate heads to water

2) hydrophilic fatty acid tails to water

Question 11

Describe have a rough endoplasmic reticulum is involved in the production of enzymes

Answer 11

The rough endoplasmic reticulum are studded with ribosomes in order to produce proteins - enzymes are proteins

Question 12

Describe have a Golgi apparatus is involved in the secretion of enzymes

Answer 12

The Golgi apparatus modifies proteins and packages them into vesicles that transport them to cell surfaces

Question 13

give two structures of bacterial cell may have a white blood cell does not

Answer 13

1) Cell wall

2) Slime layer (capsule)

Question 14

Name one organelle that you would expect to find in large numbers in a mucus secreting cell

Answer 14

mitochondria

Question 15

What is the function of the mitochondria

Answer 15

1) Aerobic respiration

2) produces ATP for energy

Question 16

True or false?

starch and cellulose can be found in plant cells

Answer 16

True

Question 17

True or false?

glycogen can be found in plant cells

Answer 17

false

Question 18

True or false?

starch, Cellulose and glycogen all contain glycocidic bonds

Answer 18

True

Question 19

True or false?

starch, cellulose and glycogen all contain alpha glucose molecules

Answer 19

false

only starch and glycogen, cellulose is composed of beta glucose molecules

Question 20

give one feature of starch that enables it to act as a storage substance

Answer 20

it is compact. it is coiled into a helical shape so more can be stored

Question 21

describe the function of chloroplasts

Answer 21

traps and absorbs light for photosynthesis

Question 22

name two structures that are present in plant cells but I’m not present in animal cells

Answer 22

1) cell wall

2) chloroplast

Question 23

why is using starch as a carbohydrate store an advantage

Answer 23

it is insoluble. this means it won’t dissolve in water and water potential isn’t affected. 

Question 24

name two structures present in an epithelial cells that are not present in bacteria

Answer 24

1) rough endoplasmic reticulum

2) Golgi apparatus

Question 25

give one advantage of using transmission electron microscope

Answer 25

It has high resolution

Question 26

Give one advantage of using an SEM rather than a TEM

Answer 26

3-D images

Question 27

What type of bond joins amino acids together in a polypeptide

Answer 27

Peptide bonds

Question 28

describe the passage of amino acids from the cytoplasm until it is secreted from the cell as a protein

Answer 28

1) In the cytoplasm
2) Through the rough endoplasmic reticulum
3) through the Golgi apparatus
4) Out the cell

Question 29

there are lots of mitochondria in cells from the pancreas explain why

Answer 29

it is the site of aerobic respiration and it produces ATP for energy

Question 30

When carrying out cell fractionation scientist homogeneous tissue, Explain why

Answer 30

To break up cells

Question 31

When carrying out cell fractionation scientist filtered the resulting suspension

Answer 31

to remove any debris or foreign things

Question 32

When carrying out cell fractionation scientist kept the suspension ice cold, explain why

Answer 32

to reduce enzyme activity this prevents cells from denaturing

Question 33

When carrying out cell fractionation scientist used an isotonic solution, explain why 

Answer 33

so osmosis doesn’t affect water potential this means cells aren’t at risk of bursting or shrinking

Question 34

Explain two ways fatty acids are important for the formation of new cells

Answer 34

1) Fatty acids are used to make phospholipid (phospholipids form membranes) the more phospholipids made, the more membranes are formed.
2) fatty acids are respired for energy this energy can be used for cell production

Question 35

there are a large number of mitochondria in epithelial cells from the small intestine, explain how mitochondria help to absorb the products of digestion

Answer 35

ATP production

Question 36

Name the process in which cells become adapted for different functions

Answer 36

cell specialisation or cell differentiation

Question 37

at what speed would you expect to find the mitochondria at the bottom of a test tube 

Answer 37

A medium speed

Question 38

When isolating mitochondria from liver cells they broke cells open in an ice cold isotonic solution explain why

Answer 38

1) ice cold: to reduce enzyme activity so the cell doesn’t denature
2) isotonic: to prevent osmosis from causing cells to burst or shrink (so water potential isn’t affected)