IMMS + Flashcards
What is oncotic pressure?
A type of osmotic pressure exerted by proteins, most notably albumin, that tend to pull fluid into their solution.
Define osmotic pressure.
The pressure that must be applied to a solution in order to prevent inward osmosis through a partially permeable membrane.
What is the cis-face of the golgi apparatus?
The face closest to the nucleus. It is the site of protein phosphorylation and receives vesicles from the endoplasmic reticulum.
What does the medial golgi do?
It modifies products by adding sugars - forms complex OLIGOSACCHARIDES by adding sugars to lipids and peptides
What does the trans golgi do?
Site of PROTEOLYSIS - converts peptides into their active forms (proteins) and sorts molecules into vesicles.
What are the functions of a cell membrane?
Insulate the cell (e.g. myelin sheath), compartmentalise cell, semi-permeable membrane allows the cell to absorb nutrients and expel waste, respond to cell signals, connects the cell to its external environment and forms a barrier to it and allows for intercellular adhesions.
What is a vesicle?
A spherical membrane bound organelle that is used to transport and store material.
What four molecules are in cell membranes?
Glycolipids, glycoproteins, cholesterol and integral proteins.
What type of collagen are basement membranes?
Type 4 collagen
What is a mis-sense mutation?
A single nucleotide change that results in a codon that codes for a different amino acid. This may lead to a dysfunctional protein or may have no effect.
How many Kcal/Kg/day is Basal Metabolic Rate?
24 Kcal/Kg/per day
How much energy is stored as triglycerides?
15kg
How much glycogen is stored and where?
350g. 200g in the liver and 150g in the muscle.
What are the three ketone bodies made by ketogenesis?
Acetoacetate, Acetone and beta-hydroxybutyrate
What is ATP and what is it made of?
Adenosine triphosphate. It is made from: 1 adenine, 1 ribose and 3 phosphates.
What are desmosomes?
A type of cell junction complex that attach cells via intermediate filaments.
Other than the Kreb’s cycle and Glycolysis, how can ATP be made?
Electron transport chain, oxidative phosphorylation, substrate level phosphorylation.
What is gonadal mosaicism?
When there are two different cell populations in the gonads. One population of cells in normal and one is mutated. All gametes from the mutated population will be affected.
What are the four phases of the growth cycle?
G1, S, G2 (interphase phase) M (mitotic phase)
At which phase in mitosis do spindles disappear?
Telophase
When does meiosis II occur?
Only after fertilisation
What is meiosis used for and when does it occur?
Used for the production of gametes. In males in begins in puberty and in females, meiosis I occurs after ovulation. and meiosis II occurs only if fertilisation takes place.
What is non-disjunction?
The failure of homologous chromosomes or sister chromatids to separate during cell division e.g. Down’s Syndrome
How is genetic diversity introduced in meiosis?
Prophase 1 - Crossing over of genetic material from non-sister chromatids
Metaphase 1 - random assortment of chromosomes