Life processes at cellular level

Semi-permeable cell membrane made up of phospholipids that are amphiphillic.

Cell membrane

Viscous fluid that contains enzymes.

Matrix

controls turgor pressure and stores dissolved minerals that are either important to cell function or are toxic wastes.

Vacuole

Transparent fluid that contains many flattened membranes called thylakoids.

Stroma

The movement of molecules across a cell membrane.

Transport

The random net movement of molecules down a concentration gradient.

Diffusion

Channel and carrier proteins help the diffusion of molecules such as amino acids, glucose and ions.

Facilitated diffusion

The passive diffusion of water across a semi-permeable membrane from an area of high concentration to an area of low concentration.

Osmosis

The movement of molecules against a concentration gradient, ATP required.

Active transport

Specialised proteins that act as biological catalysts to speed up chemical reactions in living things.

Enzymes

Activation energy is the minimum amount of energy required for a chemical reaction to occur.

Enzyme function

This is the process where plants use light, water and carbon dioxide to produce glucose and oxygen.

Photosynthesis

water + carbon dioxide —sunlight—> glucose + oxygen

Photosynthesis equation

Some enzymes need a co-factor/ co-enzyme to complete its active site.

Co-factors/ co-enzymes

Occurs in thylakoid membrane. Chlorophyll absorbs light energy. Energy splits water molecules into oxygen and hydrogen. Hydrogen produced by special molecules called NADPH.

Light dependent phase

Occurs in stroma. NADPH carries hydrogen molecules into the stroma when combined with carbon dioxide to make glucose.

Light independent phase

Process of converting glucose into ATP.

Cellular respiration

Energy molecule or energy currency of cells.

ATP

Only occurs in glycolysis in the cytoplasm. Doesn’t require oxygen.

Anaerobic respiration

Glucose —-> Lactic acid + ATP

Anaerobic respiration equation

Occurs in Glycolysis, Krebs cycle and ETC in mitochondria. Oxygen is needed.

Aerobic respiration

Glucose + Oxygen —> Carbon dioxide + water + ATP

Aerobic respiration equation

Cells divide when the distances between the cell membrane and centre of the cell becomes too large for diffusion to occur fast enough.

Why do cells divide?

Semi-conservative process because each new DNA molecule has one original parent strand and one new daughter strand.

DNA replication

Type of cell division that occurs only in somatic cells, where a parent cell divides to form two genetically identical daughter cells.

Mitosis