Science KS3 revision

Photosynthesis

A process that plants use to make their own food.

Photosynthesis Word Equation

carbon dioxide + water → glucose + oxygen

2 other components needed for photosynthesis

sunlight and chlorophyll

What do the plant roots absorb?

minerals and water

Why do plants need minerals?

to stay healthy

Why do leaves have a big surface area?

to absorb light

Where is most the chloroplasts found in a leaf?

near the top for more light

why do plants need to do photosynthesis?

Photosynthesis is important because it provides oxygen for organisms, supports the food chain, balances carbon dioxide levels, and is essential for the formation of fossil fuels and plant products

Purpose of plant veins

deliver water to cells and take glucose away

Stomata

small holes in the leaf or gas exchange (carbon dioxide goes in and oxygen goes out)

root hair tissue

small hairs on the outsides of roots which help to take in as much water as possible

Xylem tissue

the tissue which carries water up through plants from the roots

label ‘1’

eye piece

label ‘2’

Arm

label ‘3’

Lenses

label ‘4’

Focus adjustor

label ‘5’

Stage

label ‘6’

mirror

label ‘7’

Base

Why do we use a light microscope?

Cells are too small to see with the naked eye. Using a light microscope helps us to see and draw cells.

equation for aerobic respiration

Glucose + Oxygen → Carbon dioxide + Water + energy

equation for anaerobic respiration

Glucose → Lactic acid + energy

differences between aerobic and anaerobic respiration

anaerobic doesn’t need oxygen

anaerobic produces less energy

aerobic has 2 products

label ‘1’

carbohydrates

label ‘2’

fruit and vegetables

label ‘3’

protein

label ‘4’

oils and fats

label ‘5’

dairy

examples of fruit and vegetables

carrots, apples, spinach

examples of carbohydrates

bread, pasta, potatoes

examples of oils and fats

olive oil, butter, crisps

examples of dairy

milk, cheese, yogourt

examples of protein

chicken, eggs, beans

Is this an animal or a plant cell?

animal cell

label ‘1’

Nucleus

label '2’

cytoplasm

label ‘3’

Cell membrane

label ‘4’

mitochondria

Is this an animal or plant cell?

plant cell

label ‘1’

cellulose cell wall

label ‘2’

nucleus

label ‘3’

cytoplasm

label ‘4’

cell membrane

label ‘5’

large vacuole

label ‘6’

mitochondria

label ‘7’

chloroplast

cytoplasm function

where chemical reactions happen

nucleus function

controlls the cell

cell membrane function

controlls what enters and leaves the cell

mitochondria function

where respiration happens

cellulose cell wall function

strengthens and supports the cell

large vacuole function

storage space filled with cell sap

chloroplast function

make food for the the plant using photosynthesis

why do we need protein?

helps to repair cells

why do we need calcium?

strong bones and teeth

why do we need fibre?

help to keep our digestive system working

why do we need vitamins?

helps our body to keep working

why do we need fats?

a source of energy

calculating magnification

Total magnification = eye piece lens magnification × objective lens magnification

cells

the basic units from which all tissues and living things are made from

MRS GREN

movement, respiration, sensitivity, growth, reproduction, excretion, nutrition

unicellular organisms

organisms that have just one cell (bacteria, protocol, unicellular fungi, algae, archaera)

specialised

when something has features that allow it to do a particular job

respiration

being able to release energy through respiration

combustion equation

glucose + oxygen → carbon dioxide + water

reactants

the starting substances - written on left of word equation

products

the new substances made - written on right of word equation

anaerobic advantages

allows for a quick, sudden burst of energy

after strenuous excersise

lactic acid enters the blood is carried to the liver and converted back to glucose

water

about 70% of the human body is water. it is essential for chemical reactions in cells and helps transport substances in the blood. Drinking water regularly replaces the water lost through urine, sweat, and breathing.

diet

the food you eat provides the raw nutrients your body needs for energy

nutrients

food substances that provide the raw materials: fats, proteins, carbohydrates, vitamins and minerals

carbohydrates

starch and sugars

fat

liquid fats and oils. fats and oil are called lipids

fibre

made if plant cell which is not used by the body

Helps food move through the intestines and stops them getting blocked.

uses of water

a lubricant, dissolves substances to be carried around the body, fills up cells holding shape, sweat to cool you down

food labels

show the amount of different nutrients in food

starch food test

add two drops of iodine. if it turns blue-black starch is present

protein food test

add 5 drops of biuret solution if it turns purple protein is present

fat food test

rub on some white paper and hold up to the light fats will leave a greasy mark

uses of carbohydrates

the body’s main source of evergy

maintaining mass

the amount of fuel you ate using needs to be balanced by the amount you eat

kilojoules

the unit for measuring the energy in food

respiration

the process that releases energy from food

energy needs

depends on agex sexy and how active you are

vitamin a

needed for healthy skin and eyes

vitamin c

helps cells I tissues stick together properly

calcium

needed to make bones

iron

needed to make red blood cells

balanced diets

eating a range of foods in the right amount

malnutritio

having too much or too little of a nutrient in your diet

deficiency disease

caused by lacking certain nutrients for a long time

kwashiorkor

lack of protein causing a pot betty

night blindness

lack of vitamin a

scurvy

lack of vitamin c causing painful joints and bleedin

ricketts

lack of vitamin d and calcium causing bones not to form properly

anaemia

lack of iron causing tiredness and shortness or breath

starvation

lacking nearly all nutrients needed

obesity

causing by eating food containing more energy that you need

heart attack

fa clogs arteries so little blood reaches the heart