Final Review Flashcards
What are some other roles of ATP in the cell beyond anabolism?
- Synthesis of cellular molecules
- Providing molecules with negative charges
- Active transport across membranes
- Chromosome separation during mitosis/meiosis
- Inhibition or activation of proteins
- Muscle activity
Define a high energy intermediate using thermodynamic language
It is a chemical species in a reaction pathway that has a limited chemical lifetime because the products of its hydrolysis are much more stable that it is, so it has a large negative gibbs free energy, which can be used to drive other non spontaneous reactions.
Rotenone blocks
Complex I
Complex 1 is
NADH Dehydrogenase
Complex 2 is
Succinate Dehydrogenase
Complex 3 is
Cytochrome bc1
Complex 4 is
Cytochrome c oxidase
Components of the ETC
Complexes 1-4, ubiquinone, NADH, FADH2, and ATP synthase and O2 and cytochrome c
cytochrome c transfers electrons
one at a time
Antimycin A blocks electron transport in
Complex III
Cyanide and CO inhibit
Complex IV
When you add an inhibitor to the ETC, upstream of the inhibitor ______ and downstream of the inhibitor________
Components are reduced upstream and oxidized downstream
Example of decoupler
DNP
Example of ATPase blocker
oligomycin
Non competitive inhibitors change what
same Km different vmax
Competitive inhibitors change what
same vmax different Km
Lower Km is ______ affinity
higher substrate
Catalytic efficiency
kcat/Km
reduction is an increase in number of
C-H and C-C bonds
What is the end product of glycolysis and what does it feed into
pyruvate, citric acid cycle and then ETC
3 stages of glycolysis
Energy investment, glucose split, energy released
Step one glycolysis enzyme and function
Hexokinase, uses ATP to phosphorylate glucose (primes glucose to release energy later), produces glucose 6 phosphate
Step two glycolysis enzyme and function
Phosphohexose isomerase catalyses opening of ring of glucose six phosphate, then does rearrangement turning it from an aldehyde to a ketone using water
Makes fructose six phosphate, then makes it into a fructose ring
Step three glycolysis enzyme and function
Phospho-fructokinase-1, makes fructose 1-6 bisphosphate
ring has now been phosphoralated twice
Step four glycolysis enzyme and function
Opens up ring of fructose 1-6 bisphosphate, and aldolase cleaves it into two molecules
Makes glyceraldehyde 3 phosphate and dihydroxyacetone phosphate
Step five glycolysis enzyme and function
Triose phosphate isomerase turns dihydroxyacetone phosphate into glyceraldehyde 3 phosphate
All steps after step 5 of glycolysis
Occur twice because step five generates two glyceraldhyde 3 phosphates
Step six glycolysis enzyme and function
glyceraldhyde 3 phosphate dehydrogenase uses NAD to oxidize glyceraldehyde 3 phosphate, which connects it to the enzyme by a high energy thioester bond which gets replaced with a bond to an inorganic phosphate
Makes 1-3 bisphosphoglycerate
Step seven glycolysis enzyme and function
Phosphate on 1-3 bisphosphglycerate gets transferred to ADP to make ATP and 3 phosphoglycerate, enzyme is phosphoglycerate kinase
What step of glycolysis pays back the energy investment of the first three steps
The seventh step, when 2 ATP are generated (2 molecules of 1-4 bisphosphoglycerate transfer their phosphates to ADP)
Step eight glycolysis enzyme and function
Phosphoglycerate mutase makes 3 phosphoglycerate into 2 phosphoglycerate which has a better energy of hydrolysis
Step nine glycolysis enzyme and function
Enolase removes a water molecule from 2 phosphoglycerate making the last phosphate group super high energy
Step ten glycolysis enzyme and function
Transfers the high energy phosphate on 2 phosphoglycerate to ADP to make ATP, enzyme is pyruvate kinase
Net production of energetic molecules from glycolysis?
1 mole of glucose makes two moles of ATP and two moles of NADH
Steps ATP is made in glycolysis, steps NADH is made in glycolysis
ATP: 7 and 10
NADH: 6
Name the six types of enzymes
Oxidoreductases Transferases Hydrolases Lyases Isomerases Ligases
What does an oxidoreductase do
transfer electrons in the form of hydride ions or hydrogen atoms (perform redox reactions)
What does a transferase do?
transfer of a group of atoms from one molecule to another
What does a hydrolase do?
Transfer a functional group to water (performs hydrolysis reactions)
What do lyases do?
Breaks bonds between molecules without using hydrolysis, or creates double bonds by removing a molecule
What do isomerases do?
Produces isomers by moving groups around in a molecule
What do ligases do?
catalyse condensation reactions during ATP cleavage
Form bonds between two carbon atoms, or a carbon with a sulfur, oxygen, or nitrogen
What kind of enzyme is hexokinase from step one of glycolysis?
Transferase (transfers phosphate group from ATP to glucose)
What kind of enzyme is phosphohexose isomerase from step two of glycolysis?
Isomerase, opens the glucose 6 phosphate ring and then rearranges to form a ketone from the aldehyde and then puts it back into a fructose ring
What kind of enzyme is phospho-fructokinase-1 from step three of glycolysis?
Transferase, transfers a phosphate group from ATP to 1-6 bisphosphate
What kind of enzyme is Aldolase from step 4 of glycolysis?
lyase, breaks into two molecules
What kind of enzyme is Triose phosphate isomerase from step five of glycolysis
Isomerase, rearranges dihydroxyacetone phosphate into glyceraldehyde 3 phosphate
What kind of enzyme is glyceraldhyde 3 phosphate dehydrogenase in step six of glycolysis?
Oxidoreductase (NAD is reduced to NADH, then High energy intermediate phosphoralates ADP)
What kind of enzyme is phosphoglycerate kinase from step seven of glycolysis?
Transferase, moves phosphate to ADP to form ATP
What kind of enzyme is Phosphoglycerate mutase in step eight of glycolysis?
Isomerase, transfers phosphate from C3 to C2
What kind of enzyme is enolase from step 9 of glycolysis?
lyase, removes water and creates a double bond
What kind of enzyme is pyruvate kinase in step 10 of glycolysis?
Transferase, transfers phosphate to ADP
Pyruvate is turned into Acetyl CoA before entering the krebs cycle by
The pyruvate dehydrogenase complex
End products of citric acid cycle
CO2 NADH and Ubiquinone
Two purposes of the krebs cycle
Make metabolic precursors and increase cell’s ATP making potential by generating reduced electron carriers like NADH and reduced ubiquinone
Krebs/citric acid cycle takes place where in eukaryotes and where in prokaryotes
Mitochondrial matrix in eukaryotes, cytoplasm in prokaryotes
which product of glycolysis moves across the mitochondrial membrane to take part in the citric acid cycle?
pyruvate
Is the citric acid cycle anabolic or catabolic
catabolic, because we break down elements into smaller molecules and anabolic because its intermediates are used to build biological molecules
So its amphibolic
What’s an anabolic process?
Build molecules from smaller parts
What krebs cycle intermediates are used to make biological compounds?
Citrate is used for fatty acids and cholesterol
Alpha ketogluterate is used for amino acids and nucleotides
Succinal-CoA is used to make heme
Malate makes pyruvate
Oxaloacetate can be turned into glucose
What upregulates isocitrate and alpha ketoglutamate in the citric acid cycle?
High levels of ADP and Ca2+
Built in inhibition of citrate synthase
Lack of acetyl CoA, too much citrate or too much NADH
What built in inhibition is there for isocitrate dehydrogenase?
Too much NADH produced
What built in inhibition is there for alpha ketoglutarate dehydrogenase?
Too much succinyl-CoA or NADH
How many net ATP are produced by glycolysis, the citric acid cycle and oxidative phosphoralation together?
32 ATP
Anapleurotic reactions
replenish citric acid cycle intermediates
The change in G for converting ATP to ADP is
30.5KJ
Examples of Acyl phosphates from metabolic reactions
Glutamyl phosphate, succinyl phosphate, 1-3 Bisphosphoglycerate
Examples of alcohol phosphates
AMP, glyceraldehyde-3-phosphate (steps 4 and 5), 2-phosphoglycerate (steps nine)
Enol phosphate
PEP (last steps of glycolysis)
Why are alchohol phosphates not high energy intermediates?
Their products aren’t all resonance stabilized
Which carbons of glucose are released as CO2?
3 and 4
How are vitamins involved in glycolysis
NADH –> Niacin
FADH2 –> Riboflavin
CoA –> Panthothenic Acid
Prosthetic group in TCA 3
Zn 2+
TCA 4 prosthetic group and vitamin
Thiamine pyrophosphate, and thiamine
Thiamine does what
spreads out carbocationic charge
If you break off a terminal carbon group what is usually involved
TPP