BioChem 3312 Exam 1
A glycosidic bond is
A bond between an anomeric carbon atom and any -OR group
Which of the following does not undergo oxidation-reduction reactions?
ATP
The enzymes of the oxidative phosphorylation system are located in the
Cristae of the Mitochondria
The pathway followed by glucose when energy is needed
Glycolysis
Around 80% of Starch is made up of branched amylopectin
True
Humans can not digest branched cellulose because we do not synthesize the enzyme that hydrolyzes the beta-1,4 or beta-1,6 bonds along the chain
True
How many electrons are needed to fully reduce the coenzyme NAD+ to NADH/H+
2
How many high-energy bonds (phosphoanhydride bonds) does ATP contain?
2
ATP, the energy transporter of the cell, contains ____ high-energy phosphoanhydride bonds. The hydrolysis of ATP to ADP _____ energy of 7.3 kcal/mol
2, releases
The overall yield of ATP molecules from the complete catabolism of one molecule of glucose in human and other mammals is
32
How many reduced coenzymes are produced from the two carbons introduced into one round of the citric acid cycle?
4
How many stereoisomers of an aldosterone can exist?
4
Which of the following reactions is the least energetic?
AMP + H2O to give Adenosine + Pi
What is the "energy currency" in Metabolism
ATP
The common molecule produced from all foods at the second stage of catabolism is:
Acetyl-CoA
The molecule that links carbohydrate and lipid metabolism is ____
Acetyl-CoA
When energy is needed and adequate oxygen is available, pyruvate is converted to _____
Acetyl-SCoA
Which chemical is produced from pyruvate it is metabolized in muscle cells under aerobic conditions
Acetyl-SCoA
Glucose can be classified as a(n)
Aldohexose
Ribose can be classified as a(n)
Aldopentose
Starch is composed of two polymers, ____, which is an unbranched chain, and ____ which is a branched polymer
Amylose; amylopectin
The biochemical process in which simple molecules are combined to make larger ones and energy is consumed is referred to as _____
Anabolism
Glycogen is produced by ___, and its major function is ___
Animals; energy storage
The biochemical process in which complex molecules are broken down into simpler ones and energy is released is referred to as
Catabolism
The biochemical process in which complex molecules are broken down into simpler ones and energy is released referred to as
Catabolism
Which polysaccharide has only beta-1,4 glycosidic linkage?
Cellulose
The mitochondria are the location where ____ takes place and most ____ is produced
Citric acid cycle; ATP
Except for ___, all fixed complexes of the electron transport chain pumps proteins from the matrix to the inter membrane space as they transfer electrons amongst each other
Complex V (ATP synthesis)
Glycolysis occurs mainly in the
Cytosol of all cells
Which sequence illustrates the order of the steps from food to biochemically useful energy?
Digestion; acetyl-SCoA production; citric acid cycle; ATP production
Phosphorylation reactions involve the addition of a phosphate group to a molecule. Such reactions are _____ reactions and therefore____
Endergonic; require energy
Shown above is the Photosynthesis reaction. The reverse reaction of photosynthesis would be a(n) _____ reaction with deltaG= _____kcal/mol
Exergonic; -686
Ketoenol tautomerism results in the conversion of an aldose to a ketose
False (ketose to aldose
A sugar present in honey in a 50/50 ratio with glucose is
Fructose
In steps 5-8 of the citric acid cycle, the high-energy molecules ___,___, and ___ are produced, and ___ is regenerated to begin another turn of the cycle
GTP, FADH2, NADH/H+, oxaloacetate
Which of the following carbohydrates can also be used as fuel in glycolysis?
Galactose, fructose, and mannose
The process of making glucose from noncarbohydrate is known as
Gluconeogensis
Which conversion is accomplished during glycolysis
Glucose to pyruvate
Mutarotation is a process where
Glucose undergoes reaction to form an equilibrium mixture of anomers
In N-linked glycoproteins, the sugar is usually attached to the protein by a bond to the N-atom in a protein side-chain. Which amino acid below can form such a bond
Glutamine
Glycogenolysis can be correctly represented by which of the following pathways
Glycogen to glucose
Which pathway produces glucose from its storage form in animals
Glycogenolysis
In an individual who is starving or fasting, the body meets its needful glucose by the first process of ____, and then by the process of ____
Glycogenolysis; gluconeogenesis
The pathway followed by glucose when energy is needed is
Glycolysis
Glycoproteins are formed by an oligosaccharide to a protein through a ____
Glycosidic
When a monosaccharide forms a ring by interaction of one of its hydroxyl groups with its aldehyde group, the bond is referred to as a(n) ____ linkage
Hemiacetal
All of the following chemicals except ___ provide protection against potentially harmful oxygen spices
Hydrogen peroxide
The reaction in which ATP is converted to ADP with released of 7.3 kcal is (an) ____
Hydrolysis
A lack of insulin causes ____, a state in which the concentration of blood sugar is ___
Hyperglycemia; higher
When blood sugar levels are lower than normal, this condition is called
Hypoglycemia
Overproduction of insulin causes ___, a state in which the concentration of blood sugar is ___ than normal
Hypoglycemia; Lower
When a person is deprived of food, in which order does the body use the following sources to produce glucose? i. Protein breakdown to amino acids for gluconegenesis ii. Conversion of glycogen to glucose iii. catabolism of lipids
II, I, III
The proton translocating ATP synthase in located in the
Inner membrane of the mitochondrion
The disease identified as diabetes are primarily associated with a malfunction of the hormone
Insulin
The pain and cramps that occur during physical exhaustion are associated with the formation of excess
Lactate
A metabolic pathway that can be illustrated as A-->B-->C-->D--> is said to be a(n)
Linear
Gluconeogenesis occurs mainly in the
Liver
The sum of all the biochemical reactions occurring in an organism is
Metabolism
The cellular organelle associated with energy production is the
Mitochondria
The major products of carbohydrate digestion are
Monosaccharides
ATP synthesis is driven by_____
Movement of H+ ions from the inter membrane space into the mitochondrial matrix
Glycogen is most commonly found in___ cells and ___ cells
Muscle; liver
Which statement is true concerning the relationship between NAD+ and NADH
NAD+ is the oxidized form of NADH
Exergonic reactions are those that have a _____ value of deltaG and ____ spontaneous
Negative; are
Every turn of the citric acid cycle directly produces ___ molecules of ATP
One
Every turn of the citric acid cycle directly produces ____ molecules of ATP
One
____ of glucose leads to gluconic acid
Oxidation
The process of converting ADP to ATP in the mitochondrion takes place by a process known as
Oxidative phosphorylation
Cellulose is produced by ___, and its major function is ___
Plants; as a structural component
Starch is produced by ___, and its major function is ____
Plants; energy storage
Endergonic reactions are shoes that have a ____ Values of delta G are ____ spontaneous
Positive; are not
In addition to producing ATP, the citric acid cycle produces ____ as high energy molecule and ___ as its major chemical waste product
Reduced conenzymes; CO2
The electron transport chain____
Reduces O2 to H2O
Which of the following monosaccharides is present in nucleic acids?
Ribose
The target molecule(s) for a-amylase is (are)
Starch and glycogen
When ATP is produced by direct transfer of a phosphate group instead of from reactions coupled to electron transport, the process is referred to as ____ phosphorylation
Substrate-level
All of the following sugars are reducing sugars except Glucose Maltose Sucrose Lactose No Exception. All of the above are reducing sugars
Sucrose
Harmful byproducts of biochemical oxidation include
Superoxide ions and hydroxyl free radicals
Harmful byproducts of biochemical oxidation includes
Superoxide ions and hydroxyl free radicals
The ultimate source of energy for all but a very few biochemical reactions is
The Sun
Acetyl-SCoA is an intermediate in the metabolism of food molecules. Which of the following, in AcetylCoA, is the metabolically functional group that enters the citric acid cycle?
The acetyl group
The driving force which provides the energy for synthesis of ATP in the fourth stage of metabolism is
The concentration gradient of hydrogen ions between the two sides of the inner mitochondrial membrane
The fourth stage of metabolism, in which the high energy molecule from stage three are oxidized to produce ATP is referred to as
The electron transport chain
The purpose of coupling two biochemical reactions are
Use an exergonic reaction to drive an endergonic reaction
The purpose of coupling two biochemical reactions is to
Use an exergonic reaction to drive an endergonic reaction
After O2 has been reduced in the electron transport chain, the oxygen atoms are part of what molecules?
Water
The cyclic structure is the
a-D-fructose
Alpha-D-glucose and Beta-D-glucose are
anomers
Hormones which regulate glucose metabolism are ___, ___, and ___
insulin, glucagon, epinephrine
The metal that acts as an electron carrier in the cytochrome in the electron transport chain is
iron
In a coupled reaction, such as in the example shown, if the exergonic reaction releases more energy than the amount required by the endergonic reaction, the excess is _____
released as heat and used to maintain body temperature