Chapter 6- PowerPoint Lectures Flashcards
What is the capacity to do work?
energy
What are the two types of energy?
kinetic and potential
Energy of motion?
kinetic energy
stored energy?
potential energy
In a chemical reaction where is the energy transfered?
between reactants and products, and surroundings
What is the energy released or absorbed during the chemical reaction called?
energy of formation
What are the three types of systems?
isolated, closed, and open
All living organisms are what type of systems?
open
Which system doesn’t exchange material or energy with its surroundings?
iosolated
Which system exchanges only energy with its system? —doesn’t exchange matter
closed
Which system exchanges energy and matter with its surroundings?
open
What’s the first law of thermodynamics?
energy can be transformed from one form to another, but cannot be created or destroyed
What is the second law of thermodynamics?
entropy always increases
What is entropy?
disorder
What are spontaneous reactions?
reaction that doesn’t need input of energy
What two factors do you need to consider to determine if a reaction is spontanous?
change in energy content of a system and change in entropy
Reaction that have less energy in the products than the reactant tend to be?
spontaneous
reactions that absorb energy?
endothermic
Gibb’s free energy equation?
delta g = delta H- (T delta S)
In spontaneous reaction delta G is?
negative
What is delta G equal to in equilibrium?
0
What is the symbol for a reversible reaction?
double arrow
Equilibrium?
state of balance between opposing factors pushing the reaction in either direction
When do you use the terms exothermic and endo thermic?
when refering to heat
When do you use the terms exergonic and endergonic?
when referring to delta G
When do you use the terms exothermic and endothermic?
when referring to heat
Which reactions releases free energy and delta G is negative?
exergonic reactions
Which reactions must gain free energy from the surrounding to form products. also delta G is positive?
endergonic reactions
What type of reaction has more free energy in the reactants than products?
exergonic reactions
What type of reaction has more free energy in the products than reactants?
endergonic reactions
What does the graph look like for a exergonic reactions?
downward sloping hill
What does the graph look like for a endergonic reactions?
upward sloping hill
Is endergonic or exergonic reactions spontaneous?
exergonic
What are the two types of metabolic pathways?
catabolic and anabolic
What is a metabolic pathway?
series of reactions, where products of one reaciton are used as the reactant in the next reaction
In a catabolic pathway is energy released?
yes
Which metabolic pathway breaks down complex molecules to simpler compounds?
catabolic
What is the overall delta G for a catabolic pathway?
negative
What can an anabolic reaction also be called?
biosynthetic reaction
Where is energy stored in ATP
triphosphate group
what can ADP be hydrolyzed to?
AMP
what can ADP be hydrolyzed to?
AMP
What is the structure of ATP?
adenine, ribose, 3 phosphate
What is the structure of ADP?
adenine, ribose, 2 phosphate
What is the structure of AMP?
adenine, ribose, 1 phosphate
What is energy coupling?
when ATP is hydrolyzed
What is adding a phosphate group called?
phophorylation
What is the main energy component in the cell?
ATP
How is ATP continually synthesized?
ATP/ADP cycle
How many ATP are hydrolyzed and resynthesizes each second in a cell?
10 million
How does the structure of the ATP molecule store and release energy?
stored in the terminal phosphate bond, release when it is broken
How are coupled reactions important to cell function?
cells have both spontaneous and non-spontaneous reactions, need a source of energy for the non-spontaneous reactions
How are coupled reactions important to cell function?
cells have both spontaneous and non-spontaneous reactions, need a source of energy for the non-spontaneous reactions
Does the total amount of energy in the universe change in entropy?
no
Do living organisms decrease in entropy as they grow?
they seem too, but when nutrients and waste products are considered, total energy is constant and entropy increases
What is enthalpy?
potential energy in a system
What is the symbol for enthalpy?
H
What is the portion of energy in a system that is available to do work called?
free energy
What is delta S?
change in entorpy
As a system moves toward equilibrium free energy?
decreases
Do most reactions in living organisms reach equilibrium?
no b/c open systems where reactants are constant and products do not accumulate
When do organisms reach equilibrium?
when they DIE!!!
Which metabolic pathway build complicated molecules?
anabolic pathways
What is it called when an atom or molecule loses an electron?
oxidation
What is it called when an atom or molecule gains an electron?
reduction
What is a reduction and oxidation reaction called?
redox
What makes bonds unstable and ready to be broken?
activation energy
What do enzymes do?
lower activation energy
Do enzymes take part in the reaction?
no, remains the same in the beginning and the end
what are enzymes made of?
proteins
What is activation energy?
energy need to start a reaction
What is a catalyst?
lowers Activation energy and accelerates the rate of the reaction
Is an enzyme a catalyst?
yes
Do enzymes and catalysts affect delta G?
No
Are all enzymes are proteins?
yes
Are all proteins enzymes?
No
What do enzymes end with?
-ase
Can enzymes be reused?
yes
Do enzymes exist only in the cell?
No, they exist inside and outside the cell
Is lysozyme and enzyme?
yes
What is the active site?
small pocket or grove in the enzyme that the substate interacts with
What is a substrate?
what the enzyme acts on
Each enzyme catalyzes a single type of substate is referred to as?
enzyme specificity
What happens to the shape when the substrate binds to active site? what is it called?
both enzyme and substrate are distorted, making bonds ready for action
called induced fit
What happens after enzyme-substrate is formed?
substrate is converted to one or more products
What enzyme is associate with sucrose?
sucrase
What does sucrase do?
breaks down sucrose into glucose and fructose
Do we need enzymes in large quantities?
No
What is a cofactor?
nonprotein group that binds to enzyme
examples of cofactors?
metallic ions
What are coenzymes?
other cofactors are small organic molecules
Where are coenzymes often derived from?
vitamins
Which coenzymes bind tightly to enzymes?
prosthetic groups
What is superoxide diasmutase (SOD)?
free radical scavenger (bad)
What is superoxide diasmutase cofactors?
copper and zinc
What are the 3 ways enzymes stablize transition state?
bring reacting molecules together, changing shape of substate molecule, exposing reactant molecules to altered charge environment that promotes catalysis
What affects enzyme activity?
concentration of substate (concentration of cofactors), temperature, pH, control mechanisms
Does enzyme activity increase with increasing temperatures?
yes, until its optimal temperature
If substrate concentration increases/high will enzyme activity increase?
yes
What mechanisms regulate enzymes?
competitive and noncompetitive inhibition, allosteric regulation, removal or addition of chemical groups to the enzyme
What type of inhibitor is Asprin?
reversible competitive inhibitor
What does Aspirin inhibit?
enzyme cyclo-oxygenase
What type of inhibitor is Penicillin?
irreversible competitive inhibitor
What type of inhibitor is cyanide and metal ion poisoning?
noncompetitive inhibitors
What do competitive inhibitors do?
compete with the substrate for
the same active site
What do noncompetitive inhibitors do?
bind to the enzyme in a
location other than the active site—-changes shape of active site to prevent substrate from binding
What are allosteric sites
specific binding sites acting as on/off
switches
regulatory molecule binds to allosteric site to promote enzyme activity or does not bind to allosteric site to decrease enzyme activity
Do enzyme inhibitor bind to the enzyme?
yes
Do enzyme inhibitors decrease or increase enzyme activity?
decrease
What are the two confrontations for allosteric regulation?
high-affinity state (active form) and low -affinity state (inactive form)
First Law of Thermodynamics?
Energy can be transformed from one form to another, or transferred from one place to another, but it cannot be created or destroyed
Second Law of Thermodynamics?
The total disorder (entropy) of a system and its surroundings always increases (although the total energy in the universe does not change)
What is the First Law of Thermodynamic also referred to as?
principle of conservation of energy
What adds phosphate groups?
kinases
What removed phosphate groups?
phosphatases
As temperature rises, the rate of chemical reactions?
increases
Another name for optimal enzyme activity?
max enzyme activity—peak on graph
Why are the Siamese cat’s extremities darker?
enzyme that makes the darker colored pigment are optimally active at that temperature (colder in the extremities)
What type of pH is pepsin optimally active?
acidic
Where would pepsin be found?
stomach acid
Amylase enzyme found in the mouth has a pH of what for optimal activity?
7
What type of pH is trypsin optimally active?
basic
What happens to enzymes at high temperatures?
they denature
Did the RNA or DNA world come first?
RNA
Did the RNA or DNA world come first?
RNA
What are Ribozymes?
group of RNA molecules that accelerate the rate of certain reactions without being changed by the reaction
What do ribozymes in ribosomes catalyze do?
catalyze the linkage of amino acids in protein synthesis
Does a ribozyme fit the definition of an enzyme?
yes
What catalyzes the cutting and splicing reaction s that remove excess segments from RNA molecules?
ribozymes
What does feedback inhibition do?
end product is a factor in the cycle/mechanism. Can have part of controlling the cycle
Do kinases activate or deactivate an enzyme?
they do both
What is the function of phosphatases?
reverse effects of phosphorylation done by kinases
What is the function of phosphatases?
reverse effects of phosphorylation done by kinases
How does an increasing temperature affect kinetic motion?
it increases kinetic motion to break hydrogen bonds
What are the two roles ribozyme played when cellular life first appeared?
enzymes and information molecules
