biology Flashcards
Matter
all the stuff around us
-substance that takes up space and has mass
Composed of:
-elements
Atom
smallest unit of matter
Molecule
when two or more atoms join together
Ribose
5 carbon sugar (CH2O)n where n=5
Fructose
6 carbon sugar (CH2On where n=6 and is an isomer of glucose
Glucose
6 carbon sugar (CH2O)N where n=6 and is an isomer of fructose
Dissacharides
2 monomers come together via dehydration rxn or condensation rxn
What connects carbohydrates together?
glycosidic bond
Sucrose
dissacharide
-1 glucose and 1 fructose
Lactose
dissacharide
-1 galactose and 1 glucose
Maltose
dissacharide
-2 glucose monomers linked togehter
Starch
Polysaccharide
- storage in plants
- glucose monomers linear and branched
Amylose
linear plant starch
-a-1,4 glycosidic bonds
Amylopectin
branched form of plant starch
-a-1,6 glycosidic bonds
Glycogen
Polysaccharide found in humans
- storage of glucose in humans
- more branching than in starch (amylopectin)
Cellulose
Structural polysaccharide in plant cell walls
- glucose polymer
- B-1,4 glycosidic bonds
Polypeptide
Polymers of amino acids connected by peptide bonds
-form via dehydration rxn to make peptide bonds
Secondary structure of protein
intermolecular interactions between atoms of poleypetid backbone
- does not involve R groups
- Hydrogen bonding N-H
Most commne secondary proteins:
b-pleated sheets
-alpha helices
Tertiary Structure
interaction between R groups at various Aino acids:
-interactions includse: ioninc bonding, hydrogen bonding, dipole dipole interactions and London dispersions
What can denature proteins?
excess temperature
chemicals
pH changes
radiation
Protein Function
1) Storage
- reserve of amino acids
2) Hormones
- signaling molecules that circulate through the body to regulate physiological processes
3) Motion
- Movement generation for individual cells or entire organism
4) Structure
- provide strength and support to tissues
5) Immunity
- prevention and protection against foreign invaders
6) Enzymes
Enzymes
biological, globular (usually) protein catalysts that speed up specific forward and reverse reactions by lowering activation energies
Enzymes specificity constant
measures how efficient an enzyme is converting a substrate to product
-High specificity constant=High substrate affinity=highly efficient enzyme
Ribozyme
RNA molecule capable of acting like an enzyme
Cofactors
nonprotein molecules
-assist enzymes in the reaction they manipulate
Coenzymes
Organic Coenzymes
-ex: vitamins
Inorganic Coenzymes
-metal ions such as Fe2+ or Mg2+
Holoenzymes
enzymes that are bound to their cofactor
Apoenzyme
enzyme not bound to cofactor
Competitive inhibition
inhibitors compete with substrates for active sites on enzymes
-increase substrate; higher chance substrate binds to active site(outcompete)
Km Increases
-Vmax remains the same
Noncompetitive inhibition
Inhibitors bind to allosteric site of enzymes
-modifies active site so that the substrate has reducing binding or can’t bind to active site at all
Km remains the same
Vmax Decreeases
Velocity (V) or reaction
-definition
rate at which the reaction is occuring
Vmax
-definition
Maximum velocity the reaction can go
Michaelis Constant (Km)
the susbtrate concentration at which the velocity is 50% of the Vmax
- small Km=high binding affinity, only need a little bit of substrate
- large Km=low binding affinity, need a lot of substrate
Polypeptides
polymers of amino acids
Lipids
Hydrophobic, non polar molecules
-long hydrocarbon chain
Lipids function
1) Store energy
2) Provide insulation
3) contribute to cell membranes
4) synthesis of critical hormones
Triacylglycerol/triacylglyceride
Lipid Molecule: Fat -found in cells call adipocytes composed of: glycerol backbone -3 FAtty acid tails
Phospholipids
found in cell membranes LIPID MOLECULE Composed of: -glycerol backbone -one phosphate group (Polar head group) -2 FA's
AMPHipathic molecule-contain hydrophobic and hydrophilic molecules