Exam 1 Flashcards
(35 cards)
Metabolism
The totality of an organisms chemical reactions
- synthesis of macromolecules
- breakdown of macromolecules
- control of enzyme activity
Anabolism
Synthesis of macromolecules Involves bond formation Endergonic Dehydration PHOTOSYNTHESIS
Catabolism
Breakdown of macromolecules
Control of enzyme activity
CELLULAR RESPIRATION
Energy cannot
Be created by cells. It can only be crated through the flow of energy process
Exergonic
Energy is released
Cellular respiration
Endergonic
Energy is absorbed
The reactants have less potential energy than the products
First law of thermodynamics
Energy cannot be created or destroyed
Cels must acquire energy from their environment
Second law of thermodynamics
Every energy transformation is accompanied by a loss of usable energy often as heat
(Heat energy goes back into the environment- it can’t stay in the cells or else it’ll burn)
Oxidation
The gain of oxygen, the loss of hydrogen. Therefore oxidation is the loss of electrons
Reduction
Loss of oxygen
Gain of hydrogen
Gain of electrons
Activation energy
The energy needed to start a chemical reaction
All chemical reactions must overcome a thermodynamic barrier known as the reactions activation energy
Enzymes
Catalytic proteins that speed up metabolic reactions by LOWERING ENERGY BARRIERS
All reactions require a catalyst
Substrate
The reactant that an enzyme acts on. The enzyme binds to its substrate forming an enzyme substrate complex
Active site
Region on enzyme where substrate binds
Cofactors
No protein helpers required by enzymes for catalytic activity. Ie: zinc, iron and copper.
Coenzymes
Organic cofactors, include vitamins or molecules derived from vitamins.
Vitamins help stomach enzymes break down food better so the cell can get more out of it
Competitive inhibition
Enzyme inhibitors bind to the active site of an enzyme, competing with the substrate
Example; penicillin blocks the enzyme that bacteria use to make cell walls
Noncompetitive inhibitors
Bind to another part of the enzyme causing the enzyme to change structure which makes the active site less effective
Example: heavy metal poisoning or cyanide poisoning
Feedback inhibition
The end product of a metabolic pathway inhibits an early step in the pathway and shuts the pathway down
It always inhibits the first enzyme so the entire pathway is shut down. Thai prevents the cell from wasting chemical resources by continuing with the cycle/synthesizing more product than necessary
Effect of temp on enzyme activity
Too much heat may disrupt the weak bonds to change the tertiary structure of proteins= denaturation
Effect of ph on enzymes
Enzymes have optimal ph and temp in which they function
The pH is the hydrogen ion concentration which can alter the interaction between r groups that determine the tertiary structure of an enzyme resulting in a change of the active site structure
Catabolic pathways
Release stored energy by breaking down complex molecules
Redox reactions
Oxidation and reduction are coupled to make ATP
FOOD IS OXIDIZED TO CO2
OXYGEN IS REDUCED TO WATER
Glycolysis
Glucose a 6 carbon sugar is spilt into pyruvate
Substrate level phosphorylation
