key concepts

Question 1

what are eukaryotic cells

Answer 1

complex cells which include all animal and plant cells

Question 2

what are prokaryotic cells

Answer 2

smaller and simpler cells
bacteria cells

Question 3

what are eukaryotes

Answer 3

organisms made up of eukaryotic cells

Question 4

what is a prokaryote

Answer 4

a prokaryotic cells (single celled organism)

Question 5

sub cellular structures of an animal cell

Answer 5

• nucleus
• cytoplasm
• cell membrane
• mitochondria
• ribosomes

Question 6

sub cellular structures of plant cells

Answer 6

• nucleus
• cytoplasm
• cell membrane
• mitochondria
• ribosomes
• cell walls
• large vacuole
• chloroplasts

Question 7

what is a nucleus

Answer 7

contains genetic material + controls the activities of the cell

Question 8

what is a cytoplasm

Answer 8

gel like substance where most of the chemical reactions happen

Question 9

what is a cell membrane

Answer 9

holds cell together and controls what goes in and out

Question 10

what is mitochondria

Answer 10

where most of the reactions for respiration take place

Question 11

what are ribosomes

Answer 11

these are involved in translations of genetic material in the synthesis of proteins

Question 12

what is a cell wall

Answer 12

supports cell and strengthens it

Question 13

what is a large vacuole

Answer 13

contains cell sap - solution of sugar and salts maintains the internal pressure to support cell

Question 14

when are chloroplasts

Answer 14

these are where photosynthesis occurs which makes food for the plant. they contain and green substance called chlorophyll.

Question 15

factors contained in bacterial cells

Answer 15

• chromosomal DNA
• ribosomes
• cell membrane
• plasmid DNA
• flagellum

Question 16

what is flagellum

Answer 16

long hair-like structure that rotates to make the bacterium move. it can be used to move the bacteria away from harmful substances like toxins and towards things like oxygen

Question 17

attributes of a egg cell

Answer 17

1. contains nutrients in the cytoplasm to feed the embryo
2. haploid nucleus
3. after fertilisation it’s membrane changes to stop more sperm getting in

Question 18

attributed of the sperm cell

Answer 18

1. long tail to swim
2. lots of mitochondria in the middle section
3. has a acrosome at the front of the head where it stores enzymes to digest it’s way through the membrane of the egg cell
4. haploid nucleus

Question 19

what is a ciliated epithelial cells

Answer 19

lines the surface of organs to move substances in one direction along the surface of the tissue
e.g. move mucus through airways

Question 20

total magnification equ

Answer 20

total magnification =
eye piece lens magnification x objective lens magnification

Question 21

magnification equ

Answer 21

image size / real size

Question 22

how to work with a microscope

Answer 22

1. take a thin slice of your specimen, to let light through
2. next take a clean slide and you are prepared to put one drop of water in the middle of it. This will secure the specimen in place.
3. Add a drop of stain if your specimen is completely transparent or colourless this makes it easier to see
4. Place a cover slip at one end of the specimen and carefully lower onto the slide, removing any air bubbles.
5. Select the lowest powered objective lens.
6. Use the adjustment knob to move the stage up set aside is just underneath the objective lens.
7. Adjust the focus until you get a clear image.

Question 23

how is a enzymes shape important

Answer 23

enzyme has an active site which only work with one substance, if it does not fit it won’t be catalysed.
this is called ‘lock & key’ mechanism fits together

Question 24

what affects the rate of reaction and how

Answer 24

temperature - too high and it denatures
ph - to high or low interferes with the bonds holding the enzyme together
concentration - higher the concentration, faster the reaction.

Question 25

how to calculate rate of reactions

Answer 25

1000/time

Question 26

how to investigate ph effect on enzyme activity

Answer 26

1. put a drop of iodine solution into every well of a spotting tile. 2. Place a Bunsen burner on heatproof mat and a tripod and goes over the Bunsen burner put a beaker of water on top of the tripod and heat the water until 35°. 3. Using a syringe at 3 cm³ of amylase solution into 1 cm³ of a buffer solution, with a pH of 5 to boiling tube. using test tube holders, put the boiling tube into a beaker of water and wait five minutes. 4. Next use a different syringe to add 3 cm³ of starch solution to the boiling tube. 5. Immediately mix the content of the boiling tube and start the stopwatch. 6. Use continue sampling to record how long it takes for families to break down all of the starch. 7. Repeat the whole experiment with a buffer solution of different pH values to see how pH affects the time.