P3.2.1. Protein Flashcards
10 Major Categories of Proteins based on Function:
- Catalytic
- Defense
- Transport
- Messenger
- Contractile
- Structural
- Transmembrane
- Storage
- Regulatory
- Nutrient
- Enzymes are best known for their catalytic role.
- Almost every chemical reaction in the body is driven by an enzyme
catalytic proteins
Immunoglobulins or antibodies are central to functioning of the body’s immune system.
defense proteins
Bind small biomolecules, and transport them to other locations in the body and release them on demand.
e.g., oxygen and other ligands
transport proteins
- transmit signals to coordinate biochemical processes between different cells, tissues, and organs.
- regulate carbohydrate metabolism
- regulate body growth
messenger proteins
- insulin & glucagon
- human growth hormone
- necessary for all forms of movement.
- it makes sperm movement possible.
examples?
contractile proteins
ACTIN & MYOSIN: muscle contain filament-like contractile proteins.
- ## Confer stiffness and rigidity
- component of cartilage
- gives mechanical strength as well as protective covering to hair, fingernails, feathers, hooves, etc.
structural proteins
- collagen
- keratin
- Span a cell membrane and help control the movement of small molecules and ions
- have channels - enter & exit
- transport is very selective
transmembrane proteins
- Bind (and store) small molecules.
- saves iron for use in the biosynthesis of new hemoglobin molecules.
- an oxygen-storage protein present in muscle
storage proteins
- Ferritin - an iron-storage protein
- Myoglobin
- Often found “embedded” in the exterior surface of cell membranes - act as sites for receptor molecules
- Often the molecules that bind to enzymes (catalytic proteins), thereby turning them “on” and “off,” and thus controlling enzymatic action.
regulatory proteins
- Particularly important in the early stages of life - from embryo to infant.
- are nutrient proteins.
- provide immunological protection for mammalian young
nutrient protein
- Casein (milk) & Ovalalbumine (egg white)
- milk
generation of an amine and a carboxylic acid functional groups
Protein Hydrolysis
digestion of ingested protein
enzyme-catalyzed hydrolysis
what happens to free amino acids?
- absorbed in the blood stream
- transported to the liver for synthesis of new proteins
TRUE or FALSE?
Hydrolysis of cellular proteins and their re-synthesis is a continuous process.
TRUE
- Partial or complete disorganization of protein’s tertiary structure
- UNFOLDING
protein denaturation
coagulation [precipitation] and cooking
Cooking food denatures the protein but does not change protein nutritional value
- conjugated proteins with carbohydrates linked to them
- plasma membrane
- blood group marker
- collagen & immunoglobulins
glycoproteins
- Glycoproteins produced as a protective response to the invasion of microorganisms or foreign molecules
- antibodies against antigens
- occurs through hydrophobic interactions, dipole – dipole interactions, and hydrogen bonds.
immunoglobulins
- they are INSOLUBLE in water like the bloodstream and circulation in our body.
- conjugated protein that contains lipids in addition to amino acids.
- help suspend lipids and transport them through the bloodstream
lipoproteins
Four major classes of plasma lipoproteins:
- chylomicrons
- VLDL
- LDL
- HDL
Transport dietary triacylglycerols from intestine to liver and to adipose tissue.
chylomicrons
Transport triacylglycerols synthesized in the liver to adipose tissue.
VLDL
- Transport cholesterol synthesized in the liver to cells throughout the body.
- bad cholesterol
LDL
- Collect excess cholesterol from body tissues and transport it back to the liver for degradation to bile acids.
- good cholesterol
HDL
