Year 10 Content Paper 1

everything up to carbon cycle,

movement

growth response / movement of the whole organism

respiration

production of ATP - molecules which provide energy for the cell

sensitivity

detecting changes in the surroundings

control

ensuring that the chemical composition, pH and temp remains constant

growth

increase cell number

reproduction

producing offspring

excretion

getting rid of waste products

nutrition

taking in and using food

organelle

part of a cell that carries out a specific function

cell

the smallest unit of life

tissue

group of cells that have a similar shape working together for a specific function

organ

different types of tissues working together for a specific function

organ system

group of organs working together to carry out a specific function

nucleus

contains the instructions needed to control the activities of the cell. the genetic material which carries these instructions are packaged into chromosomes

vacuole

contains cell sap (store of dissolved sugars and mineral ions) which supports the shape of the cell when swollen by pushing the contents of the cell against the cell wall

cell wall

made of cellulose which supports and defines the shape of the cell as well as stops the cell from swelling too much when in water

mitochondria

site of aerobic respiration. here glucose is broken down in the presence of oxygen to release energy

ribosomes

tiny structures where proteins are made

cell membrane

partially permeable, meaning it only allows certain substances in and out of the cell and holds cell together

cytoplasm

jelly like substance which contains all of the organelles and enzymes which catalyse many reactions within the cell

features of eukaryotic organisms

linear DNA, have a nucleus, DNA stored in nucleus

features of prokaryotic organisms

circular DNA, don’t have a nucleus, DNA stored in cytoplasm

carbs are made of

glucose and sub units

proteins are made of

amino acids

lipids are made of

glycerol and fatty acids

why are carbs useful to our bodies

used to release energy in respiration

why are lipids useful to our bodies?

provide insulation and used to make cell membranes

why are protiens useful to our bodies?

growth and repair

elements in carbs

C, H, O

elements in lipids

C, H, O

elements in proteins

C, H, O, N, S

carb structure

long chains

lipids structure

fat molecules

protein structure

long chains

how to test for starch

add iodine to food solution

colour change for positive test of starch

iodine = organe/brown → dark blue/black

how to test for glucose

add benedict’s solution to food solution and heat in a water bath of 70 C

colour change for positive test of glucose

benedict’s solution = light blue → brick red

how to test lipids

add ethanol to food solution, shake gently, then add water

colour change for positive test of lipids

ethanol = colourless → milky white emulsion

how to test for protiens

add biuret’s solution to food solution and shake gently

colour change for positive test of protien

biuret’s solution = light blue → lilac

enzymes

biological catalysts in metabolic reactions

catalyst

a substance which increases the rate of reaction without being changed in the process

substrate

chemical which fits into the enzyme

active site

part of the enzyme that the substrate fits into

the substrate and enzyme fit together perfectly due to their

complimentary shape

increasing the temp of an enzyme

enzyme has more k.e. therefore will collide with the substrate more and increase the rate of reaction

above/below optimum temp of an enzyme

bonds holding enzyme together will be broken and the enzyme will loose its shape (denature) so that the substrate can no longer fit

enzyme works best at

optimum condition

diffusion

the movement of particles from an area of high concentration to an area of low concentration

factors affecting diffusion

concentration gradient, distance, temp and sa : vol

increasing temp in diffusion

particles have more k.e., so they will move faster, increasing the rate of diffusion

osmosis

the net movement of water particles from an area of high water concentration to an area of low water concentration through a partially permeable membrane

active transport

the movement of particles from an area of low concentration to an area of high concentration

active transport requires

energy

active transport gets its energy from

respiration

how does increasing the sa:vol and concentration affect diffusion

rate of diffusion increases

how does decreasing the distance affect the rate of diffusion

less distance means particles don’t have to travel as far so the rate of diffusion increases

root hair cells - osmosis and active transport

root hair cells absorb water from the soil via osmosis and they have many mitochondria to release energy to actively transport mineral ions from the soil against the concentration gradient

animal cells in pure water

become lysed. the cell membrane can’t withstand the pressure of the incoming water as it is not strong enough

plant cells in pure water

become turgid. the cell won’t swell up and burst because the cell wall protects it and the vacuole expands, pushing the contents of the cell against the cell membrane

animal cells in isotonic solutions

are normal

plant cells in isotonic solutions

are flaccid

animal cells in concentrated solutions

become shriveled as they loose water from their cytoplasm

plant cells in concentrated solutions

become plasmolyzed as their vacuoles shrink and the cell membrane pushes away from the cell wall

photosynthesis converts light energy into

chemical energy

equation for photosynthesis

6CO2 + 6H2O → C6H12O6 +6O2

carbon diffuses into the plants via the

stomata

water enters the plant via

osmosis by the root hair cells, which is then transported through the xylem of the leaf

limiting factors of photosynthesis

CO2 concentration, light intensity and temp

how does increased temp affect photosynthesis

enzymes have more k.e. therefore that rate of collisions between the enzyme and substrate increase and so does the rate of photosynthesis

how does increased light/CO2 conc affect photosynthesis

increases the rate of photosynthesis until another factor prevents the rate of reaction from increasing further because it is in short supply

leaf cell labelled top to bottom

waxy cuticle, upper epidermis, palisade mesophyll, spongey mesophyll containing the vascular bundles, lower epidermis, guard cells and cuticle

how does a large sa help the in photosynthesis

allows the leaf to absorb the maximum light possible and the leaf’s thinness allows for quick diffusion of CO2

how does the waxy cuticle help the in photosynthesis

prevents water from evaporating/reduces water loss from the leaf

how does the upper epidermis help in photosynthesis

thin and transparent allowing CO2 to diffuse quicker and for light to pass to the palisade mesophyll beneath it

how does the palisade mesophyll help in photosynthesis

it is tightly packed with chloroplasts to absorb the maximum sunlight and increase the rate of photosynthesis

how does the spongey mesophyll help in photosynthesis

air spaces allow for CO2 to diffuse easily through the leaf

what are the mineral ions needed for plant growth and why

magnesium for chlorophyll and nitrate for amino acids

what should a balanced diet contain

protein, carbs, lipids, vitamins, minerals, water and dietary fiber

sources of carbs

bread, pasta, rice

sources of protein

meats, eggs

sources of lipids

butter, oil

sources of vitamin A

animal liver, carrots

sources of vitamin C

citrus fruits

vitamin c prevents what?

scurvy

sources of vitamin D

yoghurt, milk

when does body make vitamin d?

when your skin is exposed to sunlight

sources of calcium

dairy produce

sources of iron

red meat

sources of dietary fiber

wholegrain bread, pasta

carbs - why do we need it in our diet?

body’s main fuel for supplying cells with energy

protein - why do we need it in our diet?

growth and repair of tissues

lipids - why do we need it in our diet?

used as insulation and to make cell membranes

vitamin A - why do we need it in our diet?

makes a light sensitive chemical in the retina of our eye

vitamin C - why do we need it in our diet?

sticks together the cell lining surfaces

vitamin D - why do we need it in our diet?

bone growth

calcium - why do we need it in our diet?

to make teeth and bones

iron -why do we need it in our diet?

to make haemoglobin in red blood cells, which helps carry oxygen in the blood