Biology Hidden Gems Must Memorize Flashcards
Fatty Acids
Building blocks for most but not all complex lipids.
Long chains of carbon truncated on one end by COOH.
Can be Saturated or Unsaturated (by hydrogens)
Triacylglycerols
Store Metabolic energy, provide insulation and padding.
Sometimes called triglycerides or simple fats and oils
Constructed from a three carbon backbone named glycerol
Adipocytes
Fat cells that are specialized cells where their cytoplasm contains nothing but triglycerides
Phospholipids
Serve as a constructional component of membranes.
Built from a glycerol backbone but a polar phosphate group replaces one of the fatty acids.
Amphipathic-have two charges on two different sides of the molecule.
Steroids
Four ringed structures including hormones, vitamin D, and cholesterol (a vital membrane component)
Regulate metabolic activities
Lipoproteins
Transfer lipids that are insoluble in aqueous solution
Contains a lipid core surrounded by phospholipids and apoproteins
Classified by their density. VLDL, LDL, HDL
Proteins (Polypeptides)
Built from a chain of amino acids held together by peptide bonds
Important Amino Acids
Proline-disrupts alpha-helices
Alanine-a methyl group
Glycine-just a hydrogen
Cysteine/Methionine- both contain a sulfur
Both alpha helices and beta sheets reinforced by hydrogen bonds between the carbonyl oxygen and the hydrogen on the amino group.
Five Forces Create tertiary structure
Covalent disulfide bonds between two cysteine amino acids on different parts of the chain.
Electrostatic (ionic bonds): Mostly between acidic and basic side chains
Hydrogen Bonds
Van der Wals forces
Hydrophobic side chains pushed away from water towards the center of the protein.
When you see Nitrogen THINK…
Protein
Glycoproteins
Proteins with carbohydrate groups attached
Proteoglycans
Mixture of proteins and carbohydrates
Anomers
-Alpha- When the hydroxyl group on the first carbon and the methoxy group on the 6-carbon are on opposite sides.

Glycogen
- Found in all animal cells, large amounts found in muscle and liver.
- Liver regulates blood glucose levels so they are one of the few cell types capable of reforming glucose from glycogen and releasing it back into the blood stream.
- Only certain epithelial cells in the digestive tract and the proximal tubule of the kidney are capable of absorbing glucose against a concentration gradient. This is done via secondary transport down the sodium concentration gradient.
Insulin
Increases the rate of facilitated diffusion for glucose and other monosaccharides.
In the absence of insulin only neural and hepatic cells are capable of absorbing sufficient amounts of glucose via the facilitated transport system.
Minerals
DIssolved inorganic ions inside and outside the cell. By creating electrochemical gradients they assist in the transport of stuff into and out of the cell.
Enzyme Models
Lock and Key- the active site of the enzyme has a specific shape that only binds the specific substrate
Induced fit model-The shape of both the enzyme and the substrate are altered upon binding
Enzyme Kinematics
Vmax is proportional to enzyme concentration
Km does not vary with enzyme concentration and therefore is a good indicator of an enzyme’s affinity for its substrate
Cofactor
non-protein component required by an enzyme to reach the optimal activity; either mineral or coenzyme
Apoenzyme
An enzyme without its cofactor
Coenzyme
Cosubstrates and prosthetic groups
Cosubstrates
Reversibly bind to a specific enzyme and transfer some chemical group to another substrate. The cosubstrate is then changed back to it’s original form by another enzymatic reaction
Prosthetic groups
Remain covalently bound to the enzyme throughout the reaction
Competitive inhibition
Raise the apparent Km but do not change the Vmax
Can be overcome by excess substrate


