Exam 3 Flashcards
What kind of reaction is used when you are using ADP to build up ATP?
An anabolic reaction
What kind of reaction is used when you are breaking down ATP to ADP?
A catabolic reaction
What is hydrolysis?
ATP that is released in water
What happens to the water in a hydrolysis reaction?
The water temperature rises
What are enzymes made out of?
Proteins
What do enzymes bind to?
To substrates
What part of the enzyme do substrates bind to?
The active site
What shape/form is the active site?
The same as the substrate that binds with the enzyme (it is complementary)
How do substrates bind to an active site?
By non-covalent attractions (non-covalent bonds)
What are some types of non-covalent bonds?
ionic bonds, hydrogen bonds, Vander wall attractions
What is induced fit?
When enzymes change shape to maximize interactions between amino acids and substrates
What is catalysis?
Converting the substrate to the product in the enzyme
What is the cycle of enzyme activity?
E + S forms ES then to forms into EP then it lets go of P and becomes E + P ( E = enzyme, P = product, S = substrate) LOOK AT PICTURE IN THE PICTURE TAB
In enzyme activity what does energy need to overcome to get to the product?
It needs to overcome the energy barrier
What is activation energy in enzyme activity?
The amount of energy needed to overcome the energy barrier that leads to the next lower stable state
What is the transition state in enzyme activity?
Input of activation energy
What is free energy change?
It is the free energy of the products minus the free energy of the reactants
What electrical charge will free energy always be?
Negative
What provides the activation energy that is needed to overcome the energy barrier?
Enzymes
Why are enzymes used the most to provide activation energy to overcome the energy barrier?
Because it doesn’t rely on chance collision, carries out specific reactions
Why isn’t thermal energy used that much to provide activation energy to overcome the energy barrier?
Because in lower temps they don’t have enough force or speed to bind together so the molecules bounce off each other.
In higher temps they do have enough force and speed to bind together but the probability of it happening is really low. It relies on Chance collision. And molecules/cells can die because of high temps.
What different factors affect enzyme effectiveness?
Temperature
PH levels
Substrate concentration
Presence of Co factors
presence of inhibitors
What are enzyme cofactors?
Any non-protein molecule or ion that is required for the proper functioning of the enzyme
How does temperature affect enzyme activity?
High temperature speeds up the reaction
Low temperature slows down the reaction
How does the PH levels affect enzyme activity?
PH levels need to be at the optimal level for the enzyme to be at it’s most effective point. If the PH levels are above or below the optimal level then the enzyme activity decreases.
How does substrate concentration affect enzyme activity?
Increasing substrate increases enzyme activity to a certain point until all the enzymes are bound to a substrate.
Decreasing substrate decreases enzyme activity
How does the presence of cofactors affect enzyme activity?
The increase of cofactors will increase the enzyme activity
The decrease of cofactors decreases enzyme activity drastically
How do enzymes work?
Enzymes work by lowering the activation energy required
Enzymes speed up the reaction by lowering the activation energy
What are the different types of inhibitors?
Competitive inhibitors, Allosteric regulation
What is the function of a competitive inhibitor?
They fight the substrate to the active site and turn off the enzyme
What is the function of an allosteric reaction?
They bind to the regulatory site of an enzyme and they turn on the enzyme and help with its function that it needs to perform
What function is performed for allosteric inactivation?
Binds to the regulatory site of an enzyme and turns off the enzyme so it can not perform its function
What is cooperation in an enzyme?
It is where a substrate binds to one of the active sites in an enzyme and puts all the other active sites in their active form. (basically make all of the other active sites the same)
What is feedback inhibition in an enzyme?
It is where the product of the enzyme acts as an inhibitor and goes back into the same enzyme and helps to control it (either turns it on or turns it off)
What is the active site?
The place where substrates bind to the enzyme
What is the regulatory site?
Where the allosteric activators and allosteric inhibitors bind to the enzyme and either turn it on or off.
What do cells need energy for?
chemical, mechanical, transport work
What is reduction?
the gaining of electrons
What is oxidation?
the losing of electrons
What are redox reactions?
The transfer of electrons between electrons
What follows electrons?
hydrogens
What are the 3 differences between reduction and oxidation?
Look for a change in the charge
Look for a change in the number of hydrogens
Look for a change in the number of oxygens
What are the reduced forms in each scenario?
Fe=+2 VS Fe +
NH3 VS N2
CH4 vs CO2
Fe+, NH3, CH4
What are the two ways that energy can be transferred?
- they jump down to the end and bind to the oxygen and explode
- they move step by step and release little bit of energy at a time (cellular respiration)
What carries out cellular respiration?
enzymes
What is the function of NADH+ and FAD?
to carry electrons to the electron transport chain
When NAD+ and FAD are carrying the electrons to the electron transport change. What do they turn into?
NADH and FADH2
What does glycolysis start off with?
glucose
where does glycolysis take place?
in the cytosol of the cell
what are the 2 stages in glycolysis?
The investment stage, the energy payoff stage
What happens in the investment stage in glycolysis?
It uses 5 different enzymes, has to receive 2 ATPs to start the process, and NADH+ comes in and takes the electrons and turns into NADH
What happens in the payoff stage in glycolysis?
Produces 4 ATP’s but only get a net gain of 2 ATPs, and get the molecule pyruvate
What are the inputs of glycolysis?
glucose (1), ATP (2), NAD+ (2)
What are the products of glycolysis?
pyruvates (2), ATP (4), NAD+ (2)
What is the role of Coenzyme A in pyruvate oxidation?
To make the molecule more reactive so it can interact with other molecules
Where does pyruvate oxidation take place?
in the matrix of the mitochondria
How do the pyruvates get into the matrix of the mitochondria to start the pyruvate oxidation process?
They use a transport protein
What does the pyruvate oxidation process start with?
2 pyruvates
What are the steps of the pyruvate process?
CO2 is cut off from the pyruvate, electrons are stripped and taken by NAD+ which turns into NADH, Coenzyme A attaches to from acetyl CoA
What are the inputs in the pyruvate oxidation process?
pyruvates, NAD+, CoA
What are the products in the pyruvate oxidation process?
CO2 (2), acetyl CoA (2), NAD+ (2)
Where does the citric acid cycle take place?
in the mitochondrial matrix
What does the citric acid cycle start with to begin it’s process?
Acetyl CoA
What type of electrons does FAD take to the electron transport chain?
electrons that have less energy
What type of electrons does NAD+ take to the electron transport chain?
Electrons that have more energy
What are the steps of the citric acid cycle?
Acetyl- CoA (2 carbons)is joined with Oxaloacetate (4 carbons) to make citric acid (6 carbons). Coenzyme A is released, Citric acid is oxidized in a series of oxidation reactions, 2 CO2 are released , GTP is made into ATP
What are the inputs in the citric acid cycle?
Acetyl-CoA, NAD+ (3), FAD (1), GTP +PI
What are the products in the citric acid cycle?
NADH (3), CO2 (2), GTP (1ATP), FADH2 (1)
Where does the electron transport chain take place?
in the mitochondrial membrane
What does the electron transport chain start with to start the process?
NADH, FADH2
What are the steps of the electron transport chain?
NADH and FADH2 transfer electrons to complex 1 (then turn back into NADH+ and FAD), Electrons are passed through the electron transport chain in this order. 1. complex 1 2. Coenzyme Q 3. Complex 3 4. cytochrome C 5. complex 4, With every transfer electrons give off energy (that energy is used to pump electrons, and establish a proton gradient)
What are the inputs of the electron transport chain?
NAD+
FADH2
O2
3-4 H+ (hydrogen ions)
ADP +Pi (inorganic phosphate)
What are the outputs of the electron transport chain?
NAD+
FAD
H2O
Proton gradient
3-4 H+ (hydrogen ions
ATP
What is chemiosmosis?
Where hydrogen ions and ADP + PI move down their gradient, through a channel in ATP synthase
How can chemiosmosis function? (what energy is used to do chemiosmosis?)
potential energy is used to do the work
What is the enzyme called in chemiosmosis?
ATP synthase
Where does chemiosmosis take place?
In the mitochondrial membrane
What moves through the ATP synthase in chemiosmosis?
ADP + pi, and hydrogen ions
What does Pi stand for?
inorganic phosphate
How many ATPs does chemiosmosis often times produce?
28 ATPs
How many ATPs does glycolysis produce?
2 ATP
How many ATPs does the citric acid cycle produce?
2 ATP