B2

Front 1

nucleus

Back 1

controls the activity of the cell wall

Front 2

mitochondria

Back 2

respiration occurs here for releasing energy

Front 3

chloroplast

Back 3

light energy is absorbed and changed into food here

Front 4

ribosome

Back 4

proteins are made (synthesised) here

Front 5

cell wall

Back 5

supports the and keeps its shape

Front 6

vacuole

Back 6

full of cell sap and maintains shape

Front 7

cell membrane

Back 7

controls the movement of substances in and out

Front 8

cytoplasm

Back 8

this is where many reactions takes place

Front 9

Animal cell

Back 9

ribosomes
cell membrane
cytoplasm
nucleus
mitochondria

Front 10

plant cell

Back 10

chloroplasts
vacuole
cell wall
cell membrane
ribosomes
mitochondria
nucleus

Front 11

specialised cells

Back 11

specialised cells are important because they have their own functions and features

Front 12

sperm cell

Back 12

sperm cells have a head to dive

male reproductive cells that are fertilise the egg cell

they contain mitochondria to provide energy for swimming

Front 13

red blood cell

Back 13

transports oxygen molecules throughout the body

contains a red pigment called haemoglobin- which blinds oxygen
they are disk shape

Front 14

white blood cell

Back 14

destroys pathogens
some can change shape of engulf
pathogens squeeze between other body cells
other white blood cells produce pathogens for destruction

Front 15

nerve cell

Back 15

transmits electrical signals throughout the body
they have a thin long axon, surrounded by a layer of insulating mylein(the pink outside of the axon) which increases the speed of electrical impulses
cell body has branched endings to connect to many other nerve cells

Front 16

muscle cell

Back 16

they are made from proteins
they receive an electrical impulse when they contract, this causes the muscle to shorten
can store glucose and fat, which are used when large amounts for energy are needed (protein shakes are to stronger muscles)

Front 17

diffusion

Back 17

is the movement of molecules from an area of high concentration to low concentration, until evenly spread out e.g. perfume
A difference between 2 areas is called a concentration gradient

Front 18

factors which affect diffusion

Back 18

temperature
concentration gradient

Front 19

osmosis

Back 19

osmosis is the movement of water from a high concentration from a high concentration to a low concentration

Front 20

osmosis

Back 20

plants and red blood cells use osmosis
osmosis is a partially permeable membrane (only allows certain things in and out)

Front 21

osmosis

Back 21

osmosis occurs across a semi-permeable membrane which has tiny holes in it.
these holes are small enough for water molecules to pass through but larger molecules cannot pass through

Front 22

osmosis and animal cells

Back 22

animal cells dont have a cell wall, this means they either:
swell and burst if water osmosis
shrink if too much leaves

Front 23

root hair cell

Back 23

root hair cells grow on the surface of roots and absorb water and minerals from the soil
they have long thin projections that stick.
have a large surface area for absorption

Front 24

xylem cell

Back 24

xylem vessels transport water and minerals ions up the plant.
the cells that make up these vessels are dead-they have no organelles to obstruct the water flow.
they have no cell wall

Front 25

sieve cell

Back 25

sieve cells are themain tupe of cell in sive tubes. these transport carbohydrates around the plant.
they loose their nuclei but keep cytoplasm

Front 26

palisade cell

Back 26

paliasade cells are the main site of photosynthesis.
they lie in closely packed rows underneath the upper epidermis of leaves

Front 27

epidermal cell

Back 27

epidermal cells form the top layer of cells in the leaves.
they are very thin to let sunlight pass through to the photosynthesising palisade cells, and have no chloroplasts to absorb sunlight.
they are covered by a protective waxy cuticle

Front 28

what is the formula to make a system

Back 28

cell->tissue->organ->system

Front 29

tissue

tissues in the human body are?

Back 29

tissue is the a group of cells with similar structure and function
glandular tissue
muscular tissue
epithelial tissue

Front 30

proteins

Back 30

proteins have very large molecules.
proteins are made of amino acids
proteins are needed for growth and repair
proteins:
enzymes
hormones
antibodies

Front 31

cell

Back 31

every cell has a cell membrane, nucleus and cytoplasm

Front 32

protein molecules

Back 32

protein molecules can fold up into different shapes. the shape of a protein molecule affects the way that is behaves

Front 33

enzymes

Back 33

are biological catalysts
they speed up the chemical reactions that take place inside all cells
enzymes are proteins and contain amino acids
enzymes are specific in their reaction
enzymes work best at 37 degrees (human temp)
a subtrate is joined to the active site to make an product of enzyme

Front 34

enzyme reactions

Back 34

enzymes speed up reactions by lowering the activation energy (Ea) of a reaction.
the activation energy is the energy needed to start a reaction
different reactions have different activation energies

Front 35

factors that affect the rate of a reaction

Back 35

temperature
PH
enzyme concentration
subtrate concentration
surface area
pressure

Front 36

enzyme molecule

Back 36

high temperature changes the shape of the enzyme molecule, so the enzyme stops working

Front 37

PH

Back 37

the PH also affects the shape of an enzyme.
different enzymes work best at different PH values

Front 38

why is it bad having temperature?

Back 38

digestion problems-food wont be able to break down
respiration problems- wont be able to breath
protein synthesis- cant make protein and cell in your body, and every cell in your body has protein , so creates a problem