Unit 1 Flashcards
Endoplasmic Reticulum
The endoplasmic reticulum forms a network of membrane tubules, continuous with the nuclear membrane.
Golgi Apparatus
The Golgi apparatus is a series of flattened membrane discs.
Lysosomes
Lysosomes are membrane bound organelles, that contain a variety of hydrolases that digest proteins, lipids, nucleic acids and carbohydrates.
Vesicles
Vesicles transport materials between membrane compartments.
Proteins
Proteins are polymers of amino acid monomers.
Ligand
A ligand is a substance that can bind to a protein.
Kinase
Kinase adds a phosphate onto the target protein. It catalyses the transfer of a phosphate group to other proteins.
Phosphatase
Phosphatase encourages phosphates away from the protein. It catalyses the reverse reaction from kinase.
ATPases
ATPases hydrolyse ATP
Type 1 Diabetes
Failure to produce insulin
Type 2 diabetes
Loss of insulin receptor function
Resting Membrane Potential
Resting membrane potential is a state in which there is no net flow of ions ACROSS the membrane.
Action Potential
Action potential is a wave of electrical excitation along a neuron’s plasma membrane.
Retina
The retina is the area within the eye that detects light and contains 2 types of photoreceptor cells : rods and cones.
Cytoskeleton
The cytoskeleton gives mechanical support and shape to cells.
Microtubules
Hollow cylinders composed of the protein tubulin. They control the movement of membrane bound organelles and chromosomes. They form spindle fibres that are active during cell division.
Degenerative disease
Caused by an uncontrolled reduction in the rate of the cell cycle.
Tumour formation
Caused by an uncontrolled increase in the rate of the cell cycle.
Proto-oncogene
A proto-oncogene is a normal gene, usually involved in the control of cell growth or division, but can mutate to form a tumour promoting oncogene.
Prosthetic group
A prosthetic group is a non-protein unit, tightly bound to a protein and is necessary for the proteins function.
Facilitated Diffusion
Facilitated diffusion is the passive transport of substances across the membrane through specific transmembrane proteins.
Rods
Rods contain rhodopsin to detect low levels of light
Cones
Different forms of opsin combine with retinal to give DIFFERENT photoreceptor proteins, each with a maximal sensitivity to specific wavelength : R G B UV
External death signal
External death signal molecules bind to a surface receptor protein which triggers a protein cascade within the cytoplasm.
Internal death signal
An internal death signal caused by DNA damage results in the activation of the p53 tumour suppressor protein.
Caspases
Both types of cell death signals result in the activation of caspases that cause destruction of cells. Caspases digest and break down proteins.
Prophase
Chromosomes condense and the nuclear membrane disintegrates
Metaphase
Chromosomes move and line up along the metaphase plate on the equator
Anaphase
Spindle fibres separate the sister chromatids
Telophase
The separated chromosomes form daughter nuclei
The chromosomes decondense
2 nuclear membranes form
Cytokinesis
Division of the cytoplasm
2 daughter cells formed
G1 checkpoint
Cell size is checked.
Retinoblastoma protein acts as a tumour suppressor by inhibiting the transcription of genes that code for proteins needed in DNA replication.
Phosphorylation by the G1 cyclin-CDK inhibits the Rb protein.
G2 checkpoint
The success of DNA replication and any damage to DNA is assessed.
DNA damage, triggers the activation of several proteins including p53 which can stimulate DNA repair, cell cycle arrest or cause cell death.
Metaphase checkpoint
Controls progression from metaphase to anaphase
Electrochemical gradient
The electrochemical gradient is a combination of the concentration gradient and the electrical gradient across the plasma membrane.
