Key concepts

Nucleus, cell membrane, mitochondria, ribosomes, cytoplasm

Contains DNA and controls the cell's activity

controls what goes in and out of the cell

Powerhouse of the cell where aerobic respiration takes place

site of protein synthesis

contains all organelles and nutrients, where most chemical reactions take place

Chloroplasts, cell wall and large central vacuole

Site of photosynthesis

Protects and supports the cell

Contains cell sap to keep the cell swollen

cell with a nucleus

A cell without a nucleus

chromosomal DNA, plasmid DNA, cell membrane, ribosomes and flagella

Controls the cells activities and replication, found loose in the cytoplasm

DNA that can move from one bacterium to another giving variation

To move the cell

long tail to help them swim
lots of mitochondria in cell to provide energy
acrosome enzymes in head to get through the egg
haploid nucleus

Nutrients in the cytoplasm for embryo growth
haploid nucleus
Cell membrane changes after fertilisation to ensure only one sperm gets through

Cilia are tiny hair like structures on the surface of the cell. The hairs sweep fluids and particles up the trachea

Microscopes that use rays of light that pass through lenses to magnify the object. Low magnification and resolution

They use electrons to form an image
They have a higher magnification & a higher resolution
Allow us to see smaller things in more detail

See cell structures and organelles with more detail and clarity so our understanding of them have increased

objective lens x ocular lens

Image size/actual size

milli, micro, nano, pico (100x between each)

0.2-2 micrometers

10-100 micrometers

Proteins that speed up chemical reactions

the region on the enzyme where the substrate binds

Enzymes are highly specific.(The lock and key hypothesis). Each enzyme can only catalyst one type of reaction

When the shape of their active site changes due to temperate, pH

As temperature increases enzyme activity increase until it reaches its optimum temperature then as temperature grows more, activity rate decreases as the active site becomes denatures

Each enzyme has an optimal pH at which it can perform at its maximum rate. Too low means less reactions and too high denatures the active site

As concentration increases, so does rate of reaction until it continues at the same rate since all enzymes have a substrate

amount of substrate used/ time taken

Carbohydrates, proteins and lipids are needed in the body. Their molecules are too large to pass into the blood so enzymes break them down. Once in the body, different enzymes synthesise larger molecules

To make a larger molecule from smaller ones

amylase breaks down start molecules into glucose

protease breaks down protein molecules to amino acids

Lipase breaks down lipid molecules into fatty acides and glycerol

With diffusion, osmosis or active transport

The movement of particles from an area of high concentration to an area of low concentration.

Diffusion of water through a semi permeable membrane

movement of molecules into or out of a cell against a concentration gradient. It is active as it uses energy

change in mass = (mass at the end-mass at the start/ mass at the start ) x100