Life processes at the cellular level Flashcards
Active site
A region on an enzyme that binds to a protein or other substance during a reaction.
Active transport
The movement of ion or molecules across a cell membrane into a region of higher concentration, assisted by enzymes and requiring energy.
ATP
Adenosine triphosphate is the energy carrier molecule in all living cells.
Catalyst
A substance that increases the rate of a chemical reaction without itself undergoing any permanent chemical change.
Cell
Basic building block/unit of life. The smallest functional unit of an organism.
Cell Cycle
The cell cycle or cell-division is the series of event that take place in a cell leading to its division and duplication.
Chloroplast
Organelles found in the cytoplasm of plants and is the site of photosynthesis.
Denature
A molecule (such as protein or nucleic acid) wherein its chemical structure is altered so that some of its original properties are lost or diminished.
Diffusion
The passive movement of molecules or particles along a concentration gradient, or form regions of higher to regions of lower concentration.
DNA
A self-replicating material which is present in nearly all living organisms as the main constituent of chromosomes. It is the carrier of genetic information.
Enzyme
An enzyme is a biological catalyst. This means that they speed up the chemical reactions that occur in living things but are not changed by the reaction.
Facilitated diffusion
Transport of substances across a membrane from a region of high concentration to an area of low concentration by a carrier molecule.
Ion pump
The transportation of ions against a concentration gradient through a membrane using the energy from ATP.
Mitochondria
Organelles found in the cytoplasm which are the site of cellular respiration.
Mitosis
A type of cell division that results in two daughter cells each having the same number and kind of chromosomes as the parent cell.
Nucleotide
Basic building block of nucleic acids, such as DNA and RNA. An organic compound made up of a nitrogenous base, a sugar and a phosphate group.
Organelle
An organised and specialised structure found within cells.
Osmosis
A process by which water passes through a semi-permeable membrane from a region of high concentration to an area of low concentration.
Passive transport
Transport of a substance across a cell membrane by diffusion. Energy is not required.
Phagocytosis
The process of engulfing and ingestion of particles by a cell.
Photosynthesis
Enzyme controlled process occuring in plants that use energy from sunlight to fix carbon dioxide and water in the production of glucose.
Pinocytosis
The process of taking fluid into the cell by forming narrow channels through its membrane that pinch off into vesicles.
Protein
Any of a class of nitrogenous base organic compounds which have large molecules composed of one or more long chains of amino acids.
Respiration
Enzyme controlled process that produces energy from the breakdown of glucose.
Semi-permeable membrane
A membrane that only allows certain molecules to pass through it.
Substrate
A molecule upon which an enzyme acts.
