Cell Biology Flashcards
What does the Cell Theory state ?
1) Living things are made of cells.
2) Cells are the smallest unit of life.
3) Cells come from pre-existing cells by division.
Define nutrition.
Feeding by either the synthesis of organic molecules or the absorption of organic matter.
Define metabolism.
The web of all the enzyme-catalysed reactions in a cell or organism.
Define growth.
Living things can grow or change size or shape.
Define response.
Living things can respond to and interact with the environment.
Define homeostasis.
The maintenance and regulation of internal cell conditions.
Define reproduction.
Living things produce offspring, either sexually or asexually.
Define excretion.
The removal of metabolic waste.
Define differentiation.
The development of cells in different ways to perform different functions.
Define stem cells.
Cells that are unspecialised and retain the ability to differentiate along different pathways throughout their lives.
Define induced pluripotency.
When some types of cells are reprogrammed to become pluripotent.
Define prokaryotic cells.
Cells that do not have a membrane-bound nucleus or membrane-bound organelles.
Define eukaryotic cells.
Cells that have a membrane-bound nucleus and membrane-bound organelles.
Define plasma membrane.
The membrane that surrounds a cell and controls the entry and exit of substances/nutrients in cell.
Define passive transport.
Movement of substances across cell membrane without any input of energy.
Define diffusion.
The passive movement of particles from a region of high concentration to a region of low concentration.
Define simple diffusion.
It involves particles passing between the phospholipids in the membrane.
Define facilitated diffusion.
It is when large particles diffuse through the membrane by using specific protein channels.
Define osmosis.
The passive movement of water from a region of lower solute concentration to a region of higher solute concentration through a partially permeable membrane.
Define endocytosis.
A process by which cells take in substances by surrounding them with membrane.
Define exocytosis.
A process by which cells secrete substances to external environments when vesicles fuse with the inner surface of the plasma membrane.
Define active transport.
The movement of substances across a membrane against a concentration gradient.
What are hypertonic, hypotonic and isotonic solutions and how does this affect water movement if the solutions are outside of the cells?
Hypertonic = high [solute], water leaves cell.
Hypotonic = low [solute], water enters cell.
Isotonic = same [solute], no net movement of water.
Define vesicle.
A small sac of membrane that contains various substances.
Define the endosymbiotic theory.
Organelles such as mitochondria and chloroplasts originated as symbioses between separate single-celled prokaryotic organisms.
Define interphase.
An active period in the life of a cell where many metabolic reactions occur.
Define mitosis.
The division of an eukaryotic nucleus to form 2 genetically identical nuclei.
Define cytokinesis.
The division of the cytoplasm to form 2 separate daughter cells.
Define emergent properties.
Properties that arise from the interactions between cellular components of the organism.
