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Biochemistry Final Exam

Terms in this set (199)

What interactions are the strongest?
Ion - Ion
A stronger acid has a lower/higher pKa
Lower
When will an amino acid be protinated
It will have an extra H on NH2 and no H on the O group when it is at physiological pH
Which amino acid is considered polar uncharged?
Thr
Which bond has limited rotation?
A
Asprin (acetylsalicyclic acid) has a pKa of 3.4. At pH 2 (the pH of an empty stomach) it will be primarily in the _________ form and at pH 7.4 (the pH of blood) it will be primarily in the ______ form.
Protinated, deprotinated
This is an:
Phospolipid
This is a:
Protein
Use the plot to find Km
0.4
What is the net charge at physiological pH?
-1
What is not a polar molecule?
BF3
What are lipids?
Steroids, Triglycerides, and Fatty Acids
True or False: this is a saturated fatty acid
True
True or False: The primary structure of a protein is stabilized by hydrogen bonds
False
What is an example of a nucleic acid?
DNA and RNA
Which is non-polar
Val
Tertiary structures of proteins can use ______________ to form and stabilize themselves
Hydrogen bonds, covalent bonds, hydrophobic interactions, and dispersion forces
If deltaG is positive, the reaction is
nonspontaneous and endergonic
If deltaG is negative, the reaction is
spontaneous and exergonic
Relate Kcat and efficiency
High Kcat = more efficient
Relate Km and affinity
High Km = higher affinity
What is the first committed step?
B --> C
Curve 2 shows an enzymatically catalyzed reaction with what inhibitor?
Competitive
True or False: orientation catalysis is when there is a cofactor and a single substrate
False
When the reaction rate will not change when the substrate concentration increases, this is a:
zero order reaction
An inhibitor of an enzyme decreased the Vmax, but did not change Km,. What kind of inhibitor is this?
Noncompetitive inhibitor
True of False: Acid Base catalysis occurs when a proton moves between substrates when they are bound to an enzyme
False
What mechanism of enzyme catalysis is shown
covalent
Is this an amino acid
Yes
How many non-polar amino acids are in the following peptide chain
at physiological pH?

Ala-Thr-Gln-Glu-Asp-Leu-Asn-Valine-Tyr
3
Base is added to a neutral solution containing cysteine: What group will be the first completely deprotinated?
R-group
Which is the peptide bond
a
In the polypeptide chain Glu-Asp-Leu-Asn-Val, what is on the C terminus
Val
Is an alpha helix an example of a tertiary structure?
No
What is this?
Deoxyribonucleotide
What is used for energy?
ATP
What must happen for a peptide chain to be formed from amino acids?
Dehydration
Do saturated or unsaturated fats pack together more tightly?
Saturated
What are the components of a nucleotide
nitrogenous base, sugar, phosphate group
What type of bond is formed when the electronegativity between the atoms is >2
Ionic
Is RNA usually single or double stranded?
single
What is components of amino acids?
carboxyl group, amino group, and radical group
__________ determines how fast a reaction will happen, __________ will determine if a reaction will happen
kinetics, thermodynamics
what kind of catalysis is being shown
acid-base
What is the net charge of Tyr at pH=4
0
What is the net charge of Asp-Thr at pH=1
+1
What is the net charge of Ala-Asp at pH=-1
-1
Primary structures of proteins are stabilized by:
Covalent bonds
Glucose is a:
monosaccharide
cAMP functions as a:
second messenger
This carbon is
3
This is an __-Sugar, which is the more/less common version
L, less
How many possible sterioisomers or glucose are there?
16
Does ion interaction with Ligand-Gated Ion Channel cause conformational changes to the receptor?
No
Which is the anormeric carbon?
e
The anomeric carbon is carbon number:
2
This bond is an
Alpha-1,6-glycosidic bond
This is a what kind of protein?
Integral membrane protein
True or false: in both symport and antiport, the movement of the solute across the membrane is powered by the movement of a second chemical moving from high concentration to low concentration
True
Name this 2 ways
18ωΔ6, 9 and 18Δ9, 12
These are:
constitution isomers
Is this sugar reducing or non reducing
non-reducing
What are some characteristics of a glycosidic bond
attatches something to a monosaccharide, could be O or N, catalyzed by glycosyltransferases
How many sterioisomers are possible
8
What is the name of this sugar derivative
sugar phosphate
Are sugar-sugar glycosidic bonds O or N
No
structural polysaccharides have __- linkages, which ______ by humans
Beta, which cannot be hydrolyzed
______ saturated fatty acids have less fluidity
less
Longer fatty acid tail, and more cholesteral =
less fluid
This is:
phospholipid
Effect of/response to signal binding to intracellular receptors is generally_______ (as compared to plasma membrane receptors).
slow
True of false: in crosstalk, there is interaction between multiple signalling pathways
true
Is this a pyranose?
no
What is not a common monosaccharide modification
Hydroxyl sugars
Some things about cell surface receptors:
necessary since most signals cannot cross the membrane; usually trigger a messenger; types differ in structure, ligand binding, and signal transduction mechanisms
Some things about GPCR:
sometimes have a g-protein bound, can detect light and hormones, humans have differnt types, contain 7 transmembrane proteins
True or false: G protein w/GTP bound dissociates from active GPCR to transduce signal
True
What hydrolyses GTP to GDP
alpha subunit of g-protein
Does convergence mean a single stimulus sends signals along a variety of different pathways
...
RTK signal pathway order
Ligand binding, receptor dimerization, Receptor trans-phosphorylation or self-phosphorylation, Receptors bind and activate effector proteins via phosphorylation
Lipid rafts are composed of higher concentrations of ___ than the surrounding lipid bilayer
cholesterol and sphingolipids
Lipid composition differs in (locations)
different locations of the cell, different leaflets in same location of cell, and at different locations of the same membrane
What kind of molecules move down their concentration gradient through the lipid bilayer
small polar and small hydrophobic molecules
What are characteristics of passive diffusion
fast membrane transport, use channel proteins, bind solutes with no conformational changes
What are characteristics of primary active transport
need ATP hydrolysis, solutes move against concentration gradient, need protein pump
What kind of sugars have a free aldehyde or ketone
reducing
This is
a steroid
What can move across the membrane using simple diffusion?
O2, CO2, H2O
What lipids are used for energy
Fatty acids, triacylglycerides
Is there signal transduction in ligand-gated ion channels?
No
What are linear molecules that differ at one single chiral center?
Epimers
Is a pyranose a cyclic monosaccharide?
Yes
These structures are:
Unmodified sugar, amino sugar
What is used to store energy in plants
starch
Reducing or non-reducing
reducing
The three main types of membrane lipids are:
phospoglycerides, sterols, sphingolipids
True or false: Antiport transport means 2 solutes moving through a carrier protein, one moving down its concentration gradient, the other moving up its concentration gradient, in same direction
False
How is cAMP produced
by activating adenylate cyclase
What is the function of DAG in GCPR-PLC signaling pathway
activate PKC
Polysaccharides branches are cleaved by what in human digestion?
alpha-dextrinase
The correct order of steps in human lipid digestion and absorption is:
Enzymatic digestion, micelle formation, absorption by intestinal cells, chylomicron formation
Catabolism is:
exergonic and involves the oxidation of the starting carbon-containing molecule
Which has more oxidation potential?
Lactate
Which contains more energy?
Lactate
To produce 1 pyruvate from glycerol, a net of... will be generated
1 ATP and 2 NADH
To produce 1 glucose from glycerol, a net of...will be generated/consumed
2 ATP consumed, 2 NADH generated
Production of 1 glucose from pyruvate(s) requires ____ high energy phosphoryl transfer molecules and ______ high energy electron carriers.
6, 2
What are effects of high intracellular ADP/AMP
inhibition of fructose 1,6-bisphophatase, inhibition of pyruvate carboxylase, and inhibition of PEP carboxykinase
Since carbohydrate hydrolases only cleave α- glycosidic bonds, _______ can be digested but _____ cannot be digested
starch and glycogen, cellulose and chitin
ATP directly regulates
phosphofructokinase and pyruvate kinase
Digestion of ______ requires and emulsification process
lipids
True of false: digestion occurs inside cells, metabolism occurs outside cells
false
When energy is high, there is __________ of catabolism and ___________ of anabolism
inhibition, activation
Why is glucose used for energy?
available during evolution, high energy, stable, unlikely to nonenzymatically glycosylate proteins
What is g-6-p used for in the cell?
glycolysis, nucleotide biosynthesis, glycogen formation
The reaction of generating fructose1,6-bisphosphate by phosphorylation of fructose 6-phosphate is:
irreversible
If 100 molecules of glucose are fermented, the net ATP yield would be
200
When ATP is high in cells, glycolysis is:
inhibited
What enzyme is the most important regulator of glycolysis?
phosphofructokinase
High cellular ATP levels result in a(n) _____of phosphofructokinase and a(n)____ of pyruvate kinase.
inhibition, inhibition
Are zymogens continuously released?
No
Where does gluconeogenesis occur?
liver mitochonria, cytoplasm, then ER
CoA often carries energy by carrying
Acetyl groups
___ activates pyruvate dehydrogenase and ___ inhibits pyruvate dehydrogenase
ADP, Acetyl-CoA
The citric acid cycle is important for cellular
catabolism and anabolism
In the CAC, are NAD+ and FAD oxidized?
No
When blood glucose is high, ______ secretion increases
Insulin
After a large, well-balanced meal, all of the following substances would be expected to be elevated EXCEPT:
Fatty acid
Insulin
Glucose
Glucagon
Glucogon
1. Which of the following correctly pairs an enzyme from glycolysis with its corresponding enzyme(s) used in gluconeogenesis?
a. Phosphofructokinase-1 / fructose-1,6-bisphosphatase
b. Pyruvate dehydrogenase / pyruvate carboxylase and phosphoenolpyruvate carboxykinase
c. Hexokinase / glucokinase
d. Pyruvate kinase / glucose-6-phosphatase
a
How many total molecules of ATP are synthesized from ADP via glycolysis of a single molecule of glucose?
4
Gluconeogenesis is ______, glycolysis is ________
anabolic, catabolic
What steps in glycolysis cannot be reversed in gluconeogenesis
glycolysis --> G6P
Which of enzyme catalyzes the conversion of pyruvate to oxaloacetate
pyruvate carboxylase
Conversion of 1 mol of acetyl-CoA to 2 mol of CO2 and CoA via the citric acid cycle results in the net production of
1 mol FADH2
Gluconeogenesis is a endo/exogenous process
Endogenous
In the reaction of glucose and oxygen to carbon dioxide and water, which molecule is oxidized?
glucose
During glycolysis, __________ catalyzes a step that generates ATP
phosphoglycerate kinase and pyruvate kinase
True of False: To maintain the concentration gradient and trap glucose in the cell, glucose is in dephosphorylated state
false
The reaction that converts pyruvate to oxaloacetate, happens in the:
Mitochondria
True of False: High ATP levels result in the activation of pyruvate oxidation.
False
What is an activator of Pyruvate dehydrogenase?
Pyruvate
Where does the CAC take place?
Mitochondria
What is an end product of glycolysis
Pyruvate
How many ATPs are produced from the CAC
1
True or False: A single turn of the citric acid cycle involves two different decarboxylation reactions.
True
The initial reaction of the CAC involves the addition of:
2-carbon molecule to a 4-carbon molecule
Which of the following is FALSE regarding glycolytic intermediates with high phosphoryl transfer potential.
a. Creatine phosphate is a glycolytic intermediate with high phosphoryl transfer potential.
b. 1, 3-bisphosphoglycerate is a glycolytic intermediate with high phosphoryl transfer potential.
c. Phosphoenolpyruvate is a glycolytic intermediate with high phosphoryl transfer potential.
d. Both a and b
e. Both b and c
a
True of False: all of the glycolytic kinases catalyze reactions involving ATP
True
For the production of a furan from G6P to occur, what is needed?
Isomerase
What is a product of glycolysys?
NADH
List the steps of aerobic respiration in order:
glycolysis, pyrivate ox., CAC, ox. phos.
The primary purpose of pentose phosphate pathway to:
produce NADPH and R5P
When a cell is low in ATP and high in NADP+ what will a typical human cell use glucose 6-phosphate for?
Glycolysis and all of PPP
Assuming a typical length fatty acid, one round of beta-oxidation will produce
1 NADH, 1 FADH2, 1 acetyl-CoA, and 1 acyl-CoA
The complete beta-oxidation of one steric acid molecule (C18H36O2) will result in
9 acetyl-CoA, 8 FADH2, 8 NADH, 8 H+
The second phase of the pentose phosphate pathway
is reversible, produces R5P, and is called the non-oxidative phase
What stage of cell respiration produces the most ATP
Ox. Phos.
When NADPH is high and nucleotide biosynthesis is needed
only part of part II of PPP is used
The first step of triglyceride catabolism occurs in _______ cells
adipose
What is true regarding glycerol catabolism
occurs primarily in liver cells, requires one ATP per glycerol, it generates ond NADH per glycerol
List the steps of fatty acid catabolism
activation, transport into mitochondria, beta-oxidation, entry into CAC
Q (also called coQ and ubiquinone) carries electrons that were originally brought to the ETC by____________ and transfers them directly to _______.
both NADH and FADH2, CIII
The correct order of complexes through which electrons from FADH2 travel is
CII, CIII, CIV
What rotates with the ATP synthase C ring.
Gamma
What products of glucose oxidation are essential for oxidative phosphorlation
NADH and FADH2
Which electron carrier would have the greatest negative impact on ATP production during oxidative phosphorylation if its production was inhibited?
NADH
The C-ring subunits with H+ bound are hydrophobic
True
Where does ox.phos occur?
Mitochondria
Wha of the following is a feature of oxidative phosphorylation
An electrochemical gradient accross the inner mitochondrial membrane, a membrane bound ATPase, a protonmotive force.
During electron transport, protons are pumped out of the mitochondrion at each of the major sites except for:
CII
True or False: The ATP synthase beta subunit has two different conformations
False
In the electron transport chain of aerobic organisms, which molecule is used as the terminal electron acceptor?
O2
Which of the following is TRUE regarding oxidative phosphorylation and electron carriers?
a. Electron carriers are phosphorylated before being oxidized
b. Phosphorylation drives electron carriers to lower and lower energy levels
c. Oxygen oxidation directly results in ATP production by the phosphorylation of ADP
d. Through the process of electron transfer, an electrochemical gradient is created,
and this drives the phosphorylation of ATP from ADP
d
TAGs are cleaved by ______ into glycerol and FAs
lipases
Lipases are important in converting fats into ATP. Where do they perform this function?
Intestinal lumen and adipose cells
What is the metabolite in PPP is shared with glycolysis
F6P
True or False: In fatty acid synthesis, acetyl was transported from mitochondrial to cytoplasm by malonyl CoA.
False
True or False: Low ATP levels will promote the conversion of F 6-P to ribose 5-phosphate.
False
True or False: In fatty acid synthesis, citrate is cleaved in cytoplasm to generate acetyl CoA and oxaloacetate.
True
Which of the following describe NADPH accurately?
a. NADPH is a reducing agent
b. NADPH has more energy than NADP+
c. NADPH is an anti-oxidant
d. Two of above
e. All of abovea
e
The ppp is a shunt off of:
glycolysis
Which one out of the following enzymes acts in the pentose phosphate pathway?
a. Aldolase
b. Glycogen phosphorylase
c. Pyruvate kinase
d. 6-phosphogluconate dehydrogenase
d
True or false: No ATP is produced in PPP
True
Where is ATP synthase located
mitochondrial inner membrane
Does high NADPH activate the PPP
No
True of False: Electrons are more likely to be transferred to a biomolecule with a larger E0' than one with a lower E0'.
True
What does CIV in the ETC
transfer electrons from cycochrome c to O2
True or false: F1 of ATP synthase located in inner mitochondrial membrane
false
The acyl-CoA formed in the __ is transported to the __ for oxidation
cytosol, mitochondrial matrix
If you inhibit ATP synthase, what happens (if anything) to the ETC
it halts
Synthesizing one palmitic acid molecule (C16H32O2) will require
1 acetyl-CoA + 7 malonyl-CoA + 14 NADPH + 7H+
True of False: NADPH is usually used in anabolism
True
How many molecules of NADPH are produced per molecule of glucose in the Pentose phosphate pathway?
2
When a cell is low in ATP and high in NADP+ what will a typical human cell use glucose 6-phosphate for?
Glycolysis and all of PPP
What enzyme catalyses the rate limiting step of the PPP
G6P dehydrogenase
Relative to FADH2, at what energy state does NADH enter the electron transport chain
higher
Disruption of which process will have the greatest impact on the number of electron carriers used by the electron transport chain?
The CAC
In electron transport chain, hydrogen ions are pumped from the ___ to the ___.
matrix to intermembrane space
How do the majority of fatty acids enter the mitochondria
transferase facilited entry of carnatine bound fatty acids
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