PROTEINS Flashcards
Proteins/Polypeptides
Structurally complex polymers formed by linking 20 types of monomers together called amino acids
How many types of amino acids?
20
The 20 types of amino acids:
Share similar chemical groups, unique R groups
The R-Groups influence the chemical properties of each type
Function of a protein is determined by
Its 3D structure
Denatured protein:
A protein that loses its 3D shape, which then loses its function
Protein functions
-Catalyzing metabolic reactions
-Building/repairing cells + tissues
-Transporting substances across cell membranes, within cells, + within bodily fluids
-Providing cells/tissues with physical support
-Defending the body against parasites and pathogens
-Cell signaling
-Hormonal regulation
Absence of 1 or more of the essential amino acids:
-Reduces the ability of cells to make proteins
-Disrupts cellular and bodily processes
-Medical consequences
Prion
A pathogenic (infectious) form of a protein due to its abnormal structure
Diffusion
The spontaneous movement of a substance from higher to lower concentration
Osmosis
The diffusion of water molecules across a cellular membrane
How do cells and organisms use the energy of diffusion and osmosis?
To drive amino acid transport across the cell membrane
Why must casein (breast milk protein) contain all the essential amino acids?
-Tissue and growth repair
-Enzyme and hormone production
-Immune system function
The R-Group
Provides each type of amino acid with its unique shape, size, and chemical properties
How does the structure of a protein determine its function?
-A protein’s function is due to its 3D structure
-The structure of a protein determines its ability to interact with other molecules
-Most common structures are globular and fibrous
-Lock/key mechanism
Which proteins enable other proteins to fold correctly?
Chaperone proteins facilitate the folding of >50% of proteins into their precise 3D structure
Which infectious diseases are caused by prions?
-Mad cow disease
-Kuru disease and creutzfeldt disease in humans
-Scrapies in sheep
-Chronic wasting disease in deer and elk
How are prions transmitted among host organisms?
-Eating infected meat
-Contaminated surgical equipment
Which medical disorders relate to abnormal protein structure?
-Parkinson’s disease
-Huntington’s disease
-Alzheimers
Hemoglobin
-Tetramer
-Four protein subunits
Collagen
-Timer
-Three protein subunits
Insufficient dietary intake of the essential amino acids causes
-Malnutrition
-Disrupts osmosis
-Edema
-Reduced blood protein levels decrease the osmosis of water from the body’s tissues to the blood to cause edema
% of protein intake daily
~10-35%
Storage protein
-Seeds: beans, peas, soybeans
Muscle proteins
-Actin, myosin, tropomyosin, troponin
