Topic 2 - Cells Flashcards
Active immunity
A form of immunity provided by the immune response of the body upon detection of a pathogen
Active transport
The active movement of substances from a low concentration to a higher concentration (up their concentration gradient) with the use of energy in the form of ATP
Agglutination
The clumping together of cells or particles caused by antibodies which assists phagocytosis
Antibody
A protein found in the blood that is produced by plasma cells which binds to antigens as a part of the immune response
Antigen
Marker molecules that can be detected by antibodies and trigger an immune response
Binary fission
The method of cell division used by prokaryotes involving replication of the circular DNA and plasmids followed by cytoplasmic division
Cell cycle
The series of stages preparing the cell for division consisting of interphase and mitosis.
Cell-surface membrane
A phospholipid bilayer studded with proteins that surrounds cells and separates them from their environment
Cell vacuole
A membrane bound structure found in plant cells that contains cell sap
Cell wall
A permeable layer that surrounds plant, algae and fungi cells made of polysaccharides which provides strength to the cell.
Chloroplast
An organelle found in plants and algae that is the site of photosynthesis.
Clonal expansion
The production of many genetically identical daughter cells through cell division of the activated B or T lymphocyte after clonal selection.
Clonal selection
The process of matching the antigens on an antigen presenting cells with the antigen receptors on B and T lymphocytes
Co-transport
A method of membrane transport where two substances are both transported across a membrane at the same time either in the same direction or opposite directions
Cytokinesis
Division of the cytoplasm to produce two new cells
Facilitated diffusion
The passive movement of substances from a high concentration to a lower concentration (down their concentration gradient) through transport proteins without the use of energy
Flagella
A whip-like structure found on bacterial cells that is used for cell movement.
Fluid-mosaic model
A model that describes membrane structure as a sea of mobile phospholipids studded with various proteins
Golgi apparatus
An organelle found in eukaryotic cells that is involved in the modification and packaging of proteins.
Helper T cell
A type of T cell in the immune system that stimulates cytotoxic T cells, B cells and phagocytes
Herd immunity
A type of disease immunity that occurs when a large proportion of a population are vaccinated against a disease which prevents the spread of the disease to
unvaccinated individuals.
Human Immunodeficiency Virus (HIV)
A virus that attacks T cells in the immune system
and can lead to AIDS (acquired immune deficiency syndrome).
Lysosomes
Membrane-bound vesicles found in the cytoplasm that contain a hydrolytic enzyme called lysozyme.
Magnification:
How much bigger an image appears compared to the original object calculated using the following formula
Image size = actual size x magnification
