Biology- Cell NCEA Level 2

Cytoplasm

A jelly like substance that fills the cell from the cell membrane to the nucleus, it is the site of many cellular reactions.

Endocytosis

A method of engulfing large molecules into the cell. The cell membrane surrounds he particle and draws it into the cell in a vesicle.

Nucleus

Contains and protects DNA. It is known as the cells control centre.

Nuclear Membrane

Double membrane with pore to allow large particles in and out of the nucleus.

Rough ER

ER with ribosomes attached. The ER is a network of tubes that run from the nucleus to the cell membrane. Rough ER are commonly found in cells that produce large amounts of protein for export.

Exocytosis

Exports large molecules out of the cell when a vesicle fuses with the cell membrane releasing its contents outside the of the cell.

Golgi body

Five flattened stack of membrane that modify to store and route products to their next destination.

Ribosomes

Found in prokaryotes and eukaryotes. These are involved in the making of proteins. They can be free in the cytoplasm or attached to the endoplasmic reticulum.

Vacuoles

Found in the cytoplasm, these are involved in transport.

Isotonic Solution

A concentration that is the same as that that found inside the cell. No net movement of water occurs in this situation.

Photosynthesis

A process in which light energy is converted to chemical energy. The reactants are water and carbon dioxide and the products are glucose and oxygen.

Hypertonic Solution

A strongly concentated solution. A cell in this solution would lose water by osmosis.

Hypotonic Solution

A weak solution. A cell in this solution would gain water by osmosis.

Golgi apparatus

Alternative name for Golgi body.

Plasma Membrane

Another word for cell membrane.

Respiration (equation)

C6H12O6 + 6O2 --> 6CO2 + 6H2O + ATP

Flagella

Long whip like projections that extend from the cell membrane. These enable unicellular organisms to move when flicked.

Lysosomes

Membrane bound sacs that contain digestive enzymes. These enzymes breakdown molecules and recycle cell parts.

Cytoskeleton

Microtubules and microfilaments that are found throughout the the cytoplasm, these give the cell support and maintain the shape of the cell.

Active Transport

Molecules move from a high concentration gradient to a low concentration gradient against the concentration gradient.

Facilitated Transportation

Molecules move from a high concentration to a low concentration with the help of transport proteins embedded in the cell membrane. Does not require energy.

Diffusion

Molecules move from a high to low concentration gradient. It is slow but does not require energy.

Mitochondria

Oval shaped organelle with highly folded inner membrane. This is the site of aerobic respiration in the cell where most ATP is produced.

Organelle

Part of a cell with a specific function.

Osmosis

Passive movement of water across a semi-permeable membrane from an area of high water concentration to an area of low water concentration.

Chloroplast

Photosynthetic organelles that trap sunlight energy and convert it into glucose. They contain grana and stroma.

Lactic Acid Fermentation

Produces 2 ATP molecules. Occurs in animal muscle when exercising at a high level.

Respiration

The breakdown of glucose to form ATP when oxygen is available.

Selectively permeable

The cell membrane allows some molecules through and not others.

Eukaryote Cells

These cells have a true nucleus and membrane bound organelles.

Cilia

Tiny hair like projections that extend out of the cell membrane. These cili beat in unison to remove particles from our airways.