cell structure

Question 1

function of the nucleus (3)

Answer 1

acts as the control centre through protein synthesis
retains genetic material
manufactures ribosomal RNA and ribosomes

Question 2

what is the nuclear envelope

Answer 2

double membrane with ribosomes on surface that surrounds nucleus

Question 3

function of the nuclear envelope (2)

Answer 3

controls entry and exit of materials contains reactions

Question 4

function of nuclear pores

Answer 4

allow passage of large molecules out of the nucleus

Question 5

what is the nucleoplasm

Answer 5

granular jelly like material

Question 6

what are chromosomes

Answer 6

consist of protein bound linear DNA

Question 7

what is the nucleolus

Answer 7

small spherical region within the nucleoplasm

Question 8

what is the function of the nucleolus

Answer 8

manufactures ribosomal RNA and assembles ribosomes

Question 9

what is the function of the mitochondria (2)

Answer 9

site of aerobic respiration
produces ATP

Question 10

function of the mitochondria double membrane

Answer 10

controls entry and exit of material

Question 11

what are mitochondria cristae

Answer 11

extensions of the inner membrane

Question 12

function of the mitochondria cristae

Answer 12

provide a large surface area for the attachment of enzymes

Question 13

what is the mitochondria matrix

Answer 13

contains proteins, lipids, ribosomes, and DNA

Question 14

what is the function of the mitochondria matrix

Answer 14

allows mitochondria to control the production of some of its own proteins

Question 15

what are 3 adaptations of the chloroplasts

Answer 15

1 granal membranes - large surface area for attachment (of chlorophyll etc)
2 stroma fluid contains enzymes for making sugars
3 contains DNA and ribosomes to manufacture proteins quickly

Question 15

what is the function of chloroplasts

Answer 15

to carry out photosynthesis

Question 16

what is the chloroplast envelope

Answer 16

a double plasma membrane that surrounds the chloroplast

Question 17

function of the chloroplast envelope

Answer 17

highly selective in what its allows to enter and leave

Question 18

what are the grand (in chloroplasts)

Answer 18

stacks of thylakoids where light absorption takes place

Question 19

what are thylakoids (in chloroplasts)

Answer 19

disc structures containing chlorophyll

Question 20

what is the stroma (in chloroplasts)

Answer 20

fluid filled matrix containing starch grains

Question 21

what is the function of the stroma (in chloroplasts)

Answer 21

where the synthesis of sugars takes place

Question 22

what is the endoplasmic reticulum

Answer 22

3 dimensional system of membranes that is continuous with the outer nucleus membrane
encloses a network of tubules and cisternae

Question 23

what does the rough ER have

Answer 23

ribosomes on outer surfaces of membranes

Question 24

function of the rough ER (2)

Answer 24

1 provides a large surface area for the synthesis of proteins and glycoproteins
2 provides a pathway for the transport of materials, especially proteins, throughout the cell

Question 25

how does the smooth ER differ from the rough ER

Answer 25

lacks ribosomes and is more tubular in appearance

Question 26

function of the smooth ER (2)

Answer 26

1 synthesises stores and transports lipids
2 synthesises stores and transports carbohydrates

Question 27

what is the Golgi apparatus

Answer 27

consists of cisternae and Golgi vesicles

Question 28

how does the Golgi apparatus work

Answer 28

• modifies proteins
• sorts proteins and transports them to correct destinations
• proteins transported in Golgi vesicles
• vesicles may move to the cell surface where they fuse with the membrane and release contents to the outside

Question 29

what are the functions of the Golgi apparatus (5)

Answer 29

1 add carbohydrate to proteins to form glycoproteins
2 produce secretory enzymes
3 secrete carbohydrates
4 transports, modifies and stores lipids
5 forms lysosomes

Question 30

what are lysosomes

Answer 30

formed when Golgi vesicles contain enzymes and they contain lysozymes

Question 31

what are lysozymes

Answer 31

enzymes that hydrolyse the cell wall of certain bacteria

Question 32

what are the functions of lysosomes (4)

Answer 32

1 hydrolyse material ingested by phagocytic cells
2 release enzymes via exocytosis
3 digest worn out organelles
4 completely breakdown dead cells

Question 33

what are ribosomes

Answer 33

small cytoplasmic granules made of two subunits (one big one small)

Question 34

function of ribosomes (2)

Answer 34

contain ribosomal RNA and protein
site of protein synthesis

Question 35

what kind of ribosomes in eukaryotic cells

Answer 35

80s

Question 36

what kind of ribosomes in prokaryotic cells and mitochondria

Answer 36

70s (slightly smaller than 80s)

Question 37

what is the cell wall

Answer 37

consists of a number of polysaccharides eg cellulose

Question 38

what is the fungi cell wall made of

Answer 38

chitin

Question 39

what is the algae cell wall made of

Answer 39

cellulose/glycoproteins

Question 40

function of the cell wall (3)

Answer 40

1 provides mechanical strength to prevent cell bursting from osmotic pressure
2 mechanical strength provided to plant as a whole
3 allows water to pass along it

Question 41

what is a vacuole

Answer 41

fluid filled sac bounded by a single membrane called a tonoplast
contains a solution of mineral salts, sugars, amino acids

Question 42

function of vacuole (3)

Answer 42

• supports plants by making cells turgid
• sugars and amino acids act as a temporary food store
• pigments colour petals to attract pollinators

Question 43

how do prokaryotic cells differ from eukaryotic cells

Answer 43

they are smaller and have no nucleus or nuclear envelope