test 1: ch4 Flashcards
what is a reversible reaction?
when a chemical reaction can proceed in either direction (indicated by a double arrow)
true or false: if you increase the amount of reactants that you start with, then it will increase the amount of product that you end up with
true
another name for enzymes
catalysts (because they increase the rate of the reaction
_______ increase the rate of a reaction by lowering the activation energy of the reaction
enzymes
what does denature mean?
to unfold and become inactive
reactants in a chemical reaction influenced by enzymes and interact with enzymes much like a lock and key
substrates
activity of enzymes depend on what?
the concentration of enzyme and substrates, the pH and temp of enzymes, and the concentrations of coenzymes and cofactors
names that end in -____ are named for function
-ase
derived from water-soluble vitamins and aid the enzyme
co-enzymes
a type of co-enzyme derived from vitamin B3 (niacin) - transports one hydrogen atom between enzymes
NAD
a type of co-enzyme derived from vitamin B2 (riboflavin) - transports two hydrogen atoms between enzymes
FAD
aid the enzyme by eliciting a conformational change to help substrate bind; metal ions, such as Ca2+, Mg2+, Mn2+, Cu2+, Zn2+
cofactors
energy cannot be created nor destroyed; only transformed
first law of thermodynamics
energy transformations increase the entropy (disorganization of a system
second law of thermodynamics
a reaction that requires an input of energy
endergonic reaction
a reaction that gives off energy
exergonic reaction
true or false: the amount of energy in a molecule is measured by calories
true
calorie with a capital C is known as…
1000 calories
calorie with a lowercase c is known as…
the amount of heat required to raise the temp. of 1cm3 of water 1⁰C
in oxidation-reduction reactions, a substance is _________ if:
- it loses electrons in the course of a reaction
- it gains oxygen in the course of a reaction while losing hydrogen in the course of a reaction
oxidized
LEO the lion says GER; LEO stands for…
loss of electrons = oxidation
in oxidation-reduction reactions, a substance is _________ if:
- it gains electrons in the course of a reaction
- it loses oxygen in the course of a reaction while gaining hydrogen in the course of a reaction
reduced
LEO the lion says GER; GER stands for…
gain of electrons = reduction
true or false: oxidation-reduction reactions in the body are always coupled, so if a substance is oxidized then another has been reduced and vice versa
true
in an oxidation-reduction reaction, the substance that is reduced is also called the ________ _______ because it caused another substance to be oxidized
oxidizing agent
oxidizing agents can take hydrogen away from a substance causing it to be oxidized, examples are:
NAD+ and FAD
reducing agents can donate hydrogen toa substance causing it to be reduced, examples are:
NADH and FADH2
