biology unit 1 (cells,enzymes, mvoemnet across membranes) new

Diffusion

Liquid and gas molecules moving from an area of high concentration to low

Factors affecting diffusion

Concentration gradient

tempreture

pressure

Osmosis

The diffusion of water molecules from high water concentration to low concentration across a partially permeable membrane

in osmosis what direction are molecules moving in

Both, but NET movement will be one direction

animal cell + to much water

Bursts

plant cell + to much water

Turgid

animal cells + not enough water

Flaccid

plant cell + not enough water

Placid

active transport

Movement of molecules against the concentration gradient

what dose active transport require

Energy/Atp

where is atp in active transport from

Respiration

enzyme

a biological catalyst that speeds up a reaction without being used up in it

What is an enzyme made of

Proteins (amino acids)

What happens when an enzyme and substrate molecule collide during a reaction

They form an enzyme substrate complex which then reacts to form the enzyme product

Why is the specific shape of an enzyme so important

Each enzyme catylyses a specific reaction (so need a specific shape)

What is the name of the model that shows how an enzyme works

Lock and key

Which part of the enzyme is in charge of catylsysing the reaction

Active site

What is optimum temprutrue

The tempreture at which the rate of reaction is the highest

What happens when an enzyme become denatured

The specific shape of the enzyme/active site had changed. Substrate no longer fits in the active site

What factors cause an enzyme to become denatured

High tempreture, extreme pH

Why is the specific sequence of an amino acids in an enzyme portien so important

The specific sequence of amino acids in an enzyme protein is important because they determine the shape and structure of the enzyme and the active site.

function of the cell wall

Made of cellulose to support the cell

function of the Vacuole

Contains sap

When full pushes the Cytoplasm against the wall

function fo the chloroplast

Site of photosynthesis

function of the cell membrane

Controls what gose in and out of the cell

function of the nucleus

Contains genetic material e.g DNA and controls the actions of the cell

function of the Cytoplasm

Site of most cell reaction

function of the Mitochondria

Site aerobic respiration

what are specialized cells

cells Adapted to specific function and so are more effective at carrying out these functions

how is a red blood cell spealized

It has no Nucleus contains hemoglobin and is bioconcae in shape to maximise efficency in carrying oxygen

why dose a sperm cell have a tail and lots of Mitochondria

So they can swim fast towards the egg

cellls

Smallest unit of life

tissues

A group of similar cells performing a specific function

organs

a group of diffrent tissues working together for a specific function

organ system

Organs working together

organsims

A living thing

name one advantage of an electron microscope

Allows for higher magnification

name one disadvtange of an electron mcriooscope

Can only be used on dead material

what microscope is weaker an electron or light

Light

total magnification equation

Eyepiece X objective = magnification

Name a structure in the human body that is adapted to increase the rate of diffusion.

Aveolus or villi

Explain why animal cells burst if too much water moves into them, but plant cells do not.

Animal cells don’t have a cell wall

Explain what happens when enzyme and substrate molecules collide during a reaction

The enzyme and substrate form an enzyme-substrate complex; the substrate reacts to form the product.

State the meaning of the term 'net movement'.

Particles can move in any direction but most of the particles are moving in one particular direction.

List three differences between a plant and animal cell

Plants cells have a cell wall, Vacuole and chloroplast

Note the meaning of the term 'plasmolysis'.

when the cell membrane becomes detached from the cell wall

Name two substances which diffuse into human body cells.

Oxygen and glucose