Level 2 Bio: Genetic Variation

Active transport

Movement of material against a concentration gradient, requiring energy produced during respiration.

Anaerobic respiration

Respiration without oxygen.

Aerobic respiration

Respiration with oxygen.

Catalyst

Substance which speeds up a chemical reaction without being used up itself.

Chlorophyll

Green pigment found in plants, essential for photosynthesis.

Chloroplast

Structure found in plants which is the site where photosynthesis occurs.

Cilia

Tiny strands or threads around the outside of unicellular organisms which helps them move.

Cytoplasm

The semi-liquid material inside a cell which all organelles float in.

Denatured

Enzymes that have been altered by heat.

Diffusion

The movement of material from high concentration to low concentration. This method does not require any energy.

Endoplasmic reticulum

Network of folded membranes with or without ribosomes, where many chemical reactions occur, or chemicals are transported.

Enzymes

Proteins that act as organic catalysts to speed up the rate of a chemical reaction.

Extracellular

The word that means outside the cell.

Flaccid

A cell that has lost water due to osmosis is said to be limp.

Flagella

Long hair-like strands which whip back and forth to move a unicellular organism along.

Golgi bodies

Organelle in the cytoplasm which modifies and packages secretions (proteins).

Cell membrane

The lipid bilayer that surrounds the cytoplasm of a cell.

Mitochondria

Organelles within the cell where respiration occurs.

Nucleus

The part of the cell which contains the cells genetic material and controls the cells processes.

Osmosis

The diffusion or movement of water through a semi-permeable membrane from high concentration to low.

Phagocytosis

The process by which some cells may flow around particles and engulf them.

Photosynthesis

The process by which green plants manufacture glucose from carbon dioxide and water.

Plasmolysis

The process whereby cells lose water and cause the cytoplasm to shrink away from the cell wall.

Respiration

The process by which living cells break down large organic molecules to release energy in the form ATP.

Semi-permeable membrane

A membrane which allows only some molecules to pass through, usually only smaller ones.

Specific enzyme

Enzymes which control only one type of reaction.

Turgid

A cell that is full of water due to osmosis (water moving into the cell).

Unicellular

An organism made up of only one cell.

Vacuole

A large bubble filled with watery fluid inside a cell.

Ribosomes

Site of protein synthesis.

Proteins

Enzymes, nails, hair etc. are all examples of these.

Christae

Inner folds inside a mitochondrion which increase the surface area for the reactions during respiration.

Centriole

The small structures found in animal cells which are involved in cell division.

Grana

Piles of disk like structures in a chloroplast where light is trapped & used to split the water molecule into oxygen & hydrogen.

Cellulose wall

The tough cellulose layer around plant cells which protects and supports the cell.

Lock and key model

The model by which substrates fit into the ridged active site of the enzyme.

Induced fit

The model by which substrates fit into the active site of the enzyme. The enzyme then changes shape bringing the substrates together.

High surface area to volume ratio

Small cells are better at diffusing things in and out due to their…

Contractile vacuole

The special organelle found in many fresh water unicellular organisms to expel excess water. Form of active transport (ATP needed)

Passive transport

The transport of molecules with the concentration gradient. No energy required

Active site

The place on an enzyme where the substrate fits

ATP

The main energy carrying molecule in an organism.

Organelle

The general name for the structures inside a cell.

Co-enzyme

A complex organic molecule which helps certain enzymes to function correctly.

Concentration gradient

Change in concentration between one area and another.

Cytoskeleton

A framework of microtubules inside the cytoplasm.

Electron transport chain

The series of reactions that produces ATP during respiration.

fermentation

Anaerobic respiration in plants is also called …

Eye spot

A light sensing organelle which is often found in photosynthetic aquatic unicellular organisms

Oral groove

Opening which is often found in aquatic unicellular organisms which have to feed

Glycolysis

The first stage of respiration where food is broken down into pyruvic acid

Krebs cycle

Middle stage of respiration which occurs inside the mitochondrial matrix space

Lactic acid

Toxic compound produced in animals during anaerobic respiration

Light reaction

Stage of photosynthesis where water is split by the sun’s energy

Lysosomes

Cell organelle which contains enzymes to breakdown unwanted cell components

Nucleolus

Dark stained region inside the nucleus where ribosome’s are produced

Osmoregulation

The maintenance of correct water level inside a cell/organism

phagocytes

Cells which engulf and destroy solids (foreign) matter

Pinocytosis

The process by which the cell membrane surrounds fluid to take it into the cell

Rough ER

Endoplasmic reticulum with ribosome’s attached

Smooth ER

Endoplasmic reticulum with no ribosomes attached

Stroma

‘Space’ inside chloroplasts containing starch grains and enzymes

Substrate

Substance that an enzyme acts upon

Activation energy

Energy required so a reaction can start. Enzymes often lower this