structure of cells

Question 1

function of the nucleus

Answer 1

• contains genetic material in the form of DNA and chromosomes

-makes ribosomal RNA and ribosomes

Question 2

function of nuclear envelope

Answer 2

• controls what enters and leaves the nucleus

Question 3

cristae

Answer 3

folds of the inner membrane
- increase surface area for enzymes for respiration

Question 4

what is found in the matrix

Answer 4

proteins
lipids
70s ribosomes
DNA

Question 5

function of mitochondria

Answer 5

site of aerobic respiration
produce ATP
lots of mitochondria in cells with high metabolic activity e.g muscle cell, epithelial cell- need ATP for active transport

Question 6

function of chloroplasts

Answer 6

photosynthesis for growth

contain DNA and 70s ribosomes so can make the proteins needed for photosynthesis

Question 7

what are grana

Answer 7

stacks of thylakoids
thylakoids contain chlorophyll- absorbs light

grana is where light absorption occurs

Question 8

what is stroma

Answer 8

the fluid filled matrix of chloroplasts
is where sugars are synthesised
contains enzymes needed to synthesise sugars

Question 9

rough endoplasmic reticulum

Answer 9

• has ribosomes on surface to make proteins
• provides large SA for protein synthesis
• provides a pathway to transport proteins

Question 10

smooth endoplasmic reticulum

Answer 10

• makes, stores, transports lipids
• makes, stores, transports carbohydrates

Question 11

golgi apparatus

Answer 11

• adds carbohydrates to proteins to form glycoproteins
• the modified proteins are transported by golgi vesicles to the cell surface, they fuse with the membrane and release their contents
• golgi transports, modifies, stores lipids
• forms lysosomes
• secretes carbohydrates used in production of cell wall

Question 12

lysosomes

Answer 12

fuse with vesicles and release hydrolytic enzymes

Question 13

ribosomes

Answer 13

• site of protein synthesis
  70s- found in prokaryotic cells in cytoplasm, chloroplasts and mitochondria
• 80s- found in eukaryotic cells in cytoplasm

Question 14

cell wall

Answer 14

• provides mechanical strength to prevent cell bursting under pressure created when water enters cell by osmosis

fungi cell wall- chitin
plant- cellulose
bacteria- murein

Question 15

vacuole

Answer 15

fluid filled sac surrounded by a SINGLE membrane called the TONOPLAST

• contain sugars, amino acids, mineral salts, wastes, sometimes pigments
• sugars and amino acids can act as temporary food store
• pigments may colour petals and attract insects

Question 16

define tissue
give 2 examples

Answer 16

a group of similar cells that perform a similar function
e.g epithelial tissue, xylem

Question 17

define organ
give 2 examples

Answer 17

a group of tissues that perform a specific function
e.g. stomach, leaf

Question 18

are arteries and veins organs?

Answer 18

yes
they are made up of many tissues- epithelial, muscle,

Question 19

define organ system
give 3 examples

Answer 19

a group of organs working together to carry out particular functions
e.g circulatory system, digestive system, respiratory system

Question 20

explain why an artery is described as an organ but a capillary is not

Answer 20

artery is made up of more than one tissue
but capillary made up of only one type of tissue (epithelial)

Question 21

eukaryotic cells produce and release proteins
outline the role of organelles in production, transport and release of proteins (4)

Answer 21

1. DNA in nucleus is code (for protein);
2. Ribosomes/rough endoplasmic reticulum
   produce (protein);
3. Mitochondria produce ATP (for protein
   synthesis);

4 Golgi apparatus package/modify;

5 Vesicles transport

6. (Vesicles) fuse with cell membrane;