(P1+P2) Topic 1: Key Concepts

Question 1

Calculation to convert metres (m) to millimetres (mm)

Answer 1

x1000

Question 2

Calculation to convert millimetres (mm) to micrometers (μm)

Answer 2

x1000

Question 3

Calculation to convert micrometers (μm) to nanometres (nm)

Answer 3

x1000

Question 4

Calculation to convert nanometres (nm) to picometres (pm)

Answer 4

x1000

Question 5

Calculation to work out total magnification

Answer 5

Total magnification = eyepiece lens x objective lens

Question 6

Name the components of a plant cell (7 things)

Answer 6

Cell wall
Cell membrane
Vacuole
Nucleus
Mitochondria
Cytoplasm
Chloroplast

Question 7

Name the components of an animal cell (5 things)

Answer 7

Ribosomes
Mitochondria
Cytoplasm
Nucleus
Cell membrane

Question 8

What does the nucleus contain

Answer 8

DNA

Question 9

What do mitochondria do

Answer 9

Respiration and release energy

Question 10

What does the cell wall do

Answer 10

Strengthens the cell

Question 11

What do chloroplasts do

Answer 11

Photosynthesis

Question 12

What do ribosomes do

Answer 12

Synthesise protein

Question 13

What does the cell membrane do

Answer 13

Controls what goes in and out of the cell

Question 14

Name the 7 nutrients

Answer 14

Minerals
Vitamins
Protein
Carbohydrates
Fats
Fibre
Water

Question 15

What is the food test for starch

Answer 15

Iodine
Goes blue-black in starch
Orange in no starch

Question 16

What is the food test for sugar

Answer 16

Benedict’s +heat (90°)
Yellow orange/ brick red = sugar present
Blue = no sugar present

Question 17

Food test for fat

Answer 17

Ethanol + shake
Milky white = fat present
Clear and colourless = no fat present

Question 18

Food test for protein

Answer 18

Biuret
Purple = protein present
Blue = no protein present

Question 19

What is the cell wall made of

Answer 19

Cellulose

Question 20

What is a catalyst

Answer 20

Something that speeds up a reaction

Question 21

What is an enzyme

Answer 21

A biological catalyst

Question 22

What does denatures mean

Answer 22

When a cell can’t work anymore due to too high or low temp, too high or low pH, etc

Question 23

What is physical digestion + examples

Answer 23

Breaking large pieces of food into smaller pieces e.g chewing, stomach churning

Question 24

What are enzymes made out of

Answer 24

Amino acids

Question 25

Factors that effect enzymes (4 things)

Answer 25

Temperature pH Surface area Concentration

Question 26

What is chemical digestion and why does it occur

Answer 26

Breaking down large molecules into smaller molecules. It requires enzymes. Molecules need to be small do they can be absorbed through the gut wall into the blood

Question 27

Why does bile emulsify fats

Answer 27

Because water and fat don’t mix

Question 28

Define diffusion

Answer 28

The movement of a substance from an area of high concentration to an area of low concentration, down the concentration gradient

Question 29

What are the factors that affect diffusion (4)

Answer 29

Temperature surface area to volume ratio thickness of membrane concentration gradient

Question 30

What is Fick’s Law

Answer 30

Rate of diffusion ∝ concentration gradient x surface area / thickness of membrane ∝ means approximately

Question 31

What is facilitated diffusion

Answer 31

Special diffusion, carrier proteins let large molecules in

Question 32

Define osmosis

Answer 32

Diffusion of water across a partially permeable membrane

Question 33

Define active transport

Answer 33

Movement of ions against the concentration gradient. This requires energy

Question 34

Calculation for image size

Answer 34

Image size = actual size x magnification