Biochem Flashcards
1
Q
Maltose is produced from the breakdown of which of the following?
A
Starch
2
Q
Which vitamin is necessary for oxidative decarboxylation during carbohydrate metabolism?
A
Thiamine
3
Q
The final products of aerobic metabolism of carbohydrate are:
A
Carbon dioxide and water
4
Q
Gluconeogenesis is stimulated by which hormone?
A
Cortisol;
If cortisol is not available as an answer, choose epinephrine
5
Q
Which of the following will reduce to only two glucose molecules?
A
Maltose
6
Q
What type of reaction makes pyruvate and oxaloacetate from aspartate + asparagine?
A
Transamination;
Transamination will convert sugar into an amino acid.
7
Q
The catabolism of glucose begins with the transferring of phosphate groups from ATP in a reaction catalyzed by:
A
Hexokinase
8
Q
Excessive fluoride in drinking water will cause:
A
Discoloration of teeth
9
Q
Which of the following is the sugar component of ATP?
A
Ribose
10
Q
Which is a non-reducing sugar?
A
Sucrose
11
Q
The most common bond between the glucose moieties in glycogen is:
A
Alpha 1-4
12
Q
Sucrose is a non-reducing sugar because it:
A
Undergoes mutarotation;
Mutarotation is left and right rotation.
13
Q
Which carbohydrate is the most prevalent sugar in blood plasma?
A
Glucose
14
Q
What is a six-membered ring of a monosaccharide called?
A
Pyranose
15
Q
Which carbon, on a 6-carbon fatty acid, determines the D versus L configuration of a sugar carbon?
A
5
16
Q
Which of the following can be catabolized anaerobically?
A
Glucose
17
Q
Which of the following is classified as a complex carbohydrate?
A
Amylose
18
Q
Which of the following occurs with a low carbohydrate diet?
A
Glucogenesis;
Lipogenesis, ketosis, and fatty acid mobilization all realte to fat! Apple, orange, banana, RAT - The “rat” is glucogenesis, which is the answer!
19
Q
Which dietary carbohydrate does NOT require digestion before being absorbed?
A
Fructose
20
Q
What are the products of carbohydrate digestion?
A
Monosaccharides
21
Q
Dietary fiber is described as:
A
Undigestible carbohydrates
22
Q
Galactose is the product in the digestion of:
A
Lactose
23
Q
Which diet will most likely produce ketosis?
A
Low carbohydrate
24
Q
Fat mobilization is promoted by ___ and inhibited by ___.
A
Epinephrine; insulin
25
Glycolysis stimulates which of the following?
Lipid storage in fat cells
26
What enhances the biosynthesis of triglycerides in adipose tissue?
Increased glucose uptake in adipose cells
27
An intermediate in gluconeogenesis from lipids is
Glycerol-3-phosphate
28
Bile accomplishes which of the following?
Emulsification of fats;
Hydrolysis is accomplished through various enzymes. Emulsification is the first step of fat digestion and allows the enzymes for fat hydrolysis to perform their duties.
29
Cholesterol synthesis is stimulated by:
Insulin;
| Glucagon, epinephrine, and norepinephrine inhibit cholesterol synthesis
30
The presence of which of the following metabolites in the blood inhibits the production of cholesterol by the liver?
Cholesterol
31
Chylomicrons are synthesized by ___ cells.
Intestinal
32
Fatty acid oxidation yields more energy per gram than does sugar oxidation because fatty acids:
Can exist initially in a more reduced state than sugars
33
With the normal process of biosynthesis, which of the following is the most vital part of the lipid bilayer?
Phosphatide;
| Ketones are produced from fat metabolism.
34
Which is a complex lipid which contains carbohydrates in their structure?
Cerebroside;
| Sphingomyelinase deficiency is called Niemann-Pick disease
35
Transfer of fatty acids to cytoplasm of the mitochondrial matrix is by way of:
Carnitine;
| It takes a "car" nitine to drive the fatty acids into the membrane
36
Which of the following is NOT an essential fatty acid?
Palmitic
| Arachidonic, Linoleic, Linolenic are
37
Which classes of compounds constitute major components of dietary lipids?
Triacylglycerols
38
Which is a bond between glycerol and fatty acids?
Ester
39
When a polar lipid such as lecithin is suspended in water, a bimolecular layer is spontaneously formed to:
Hide the hydrophobic tails and expose the hydrophilic heads
40
Which of the following is absorbed into the lymphatics to a greater extent than in the blood during the process of digestion?
Fats
41
Which of the following oils has the highest level of monounsaturated fatty acids?
Olive oil
42
Which of the following fatty acids is NOT endogenously synthesized in the body?
Linoleic
| Palmitic, Palmitoleic, Oleic
43
Which of the following is the major dietary source of omega-3 fatty acids?
Cold water fish oil
44
The first stage of protein synthesis includes:
Activation;
The stages of protein synthesis: 1. Activation of amino acids, 2. Initiation of polypeptide chain, 3. Elongation, 4. Termination, 5. Folding and processing.
45
Where is the primary site of amino acid metabolism?
Liver
46
Nitrogen is excreted in protein catabolism combined for use with:
Amino acid
47
Thyroid hormone biosynthesis includes iodination of which amino acid?
Tyrosine
48
From which amino acid is niacin synthesized?
Tryptophan;
| Tryptophan mostly makes what ends in "N."
49
What is the cause of phenylketonuria?
Inability to convert phenylalanine to tyrosine
50
Which amino acid directly supplies the amino group of synthesis of other amino acids?
Glutamine
51
The most common amino acid in the production of renal ammonia is:
Glutamine
52
What amino acid is not optically active?
Glycine;
Optically active amino acids can rotate plane-polarized light in one direction or the other. Glycine is the ONLY amino acid that is not optically active!
53
What amino acid is predominant in the transport of nitrogen between organs?
Alanine and glutamine
54
What is the term for an amino acid ion that has both positive and negative regions of charge?
Zwitterion
55
What is an element of protein, but NOT of fatty acid?
Nitrogen
56
The amino acid sequence of a protein is known as which structure?
Primary
57
Which amino acid contains sulfur?
Cysteine;
| Methionine also contains sulfur.
58
Human plasma contains the greatest amount of which of the following proteins?
Albumin;
| 1:2 Albumin to Globulin ration.
59
Which of the following begins with serine?
Synthesis of glycine
60
Digestion of proteins in the stomach is the function of:
Pepsin
61
Which food contains the highest quality protein?
Egg
62
What is the source of utilizable nitrogen for the human body?
Protein
63
Digestion of protein is a function of:
Trypsin;
| Carbohydrate digestion begins in the mouth with salivary amylase (ptyalin).
64
During the digestion of proteins which of the following reactions occur?
Hydrolysis
65
Which of the following is a very poor source of tryptophan?
Lamb
66
Chylomicronemia is caused by a deficiency of:
Lipoprotein lipase
67
Digestive proteins are absorbed from the GI tract predominantly as:
Amino acids;
| Amino acids are the simplest form of proteins.
68
The catalytic function of an enzyme is to:
Decrease a reaction’s activation energy
69
Enzymes which have different structures and catalyze the same reactions are known as:
Isoenzymes;
Coenzymes help enzymes work, proenzymes are enzyme precursors, allosteric enzymes control the rate of reactions, and isoenzymes are enzymes with different subgroups but similar main groups in their structure.
70
Glucose-6-phosphate dehydrogenase is under what enzyme classification?
Oxidoreductase
71
Which of these enzymes catalyze the conversion of glycogen to glucose-1-phosphate during glycogenolysis?
Glycogen phosphorylase
72
An albino, who is completely white, is lacking which enzyme in his melanocytes?
Tyrosine hydroxylase;
| Tyrosine hydroxylase is necessary for the synthesis of melanin.
73
The third step of glycolysis involves the allosteric enzyme:
Phosphofructokinase
74
Selenium is a cofactor for which enzyme?
Glutathione peroxidase
75
Which of the following enzymes regulates cholesterol biosynthesis?
HMG-CoA reductase
76
Which of the following is a cofactor for hexokinase?
Adenosine triphosphate
77
Enzymes function by ____ reactions.
Decrease entropy
78
Which of the following hormones increase the activity of the tricarboxylic acid cycle?
Thyroxine
79
The principle source of utilizable androgens in the human is:
Fats;
| Steroid hormones are made from fat.
80
In humans, prostaglandins are primarily derived from:
Arachidonate
81
Beta dopamine is necessary for the synthesis of:
Norepinephrine
82
Hydroxymethyl glutaryl CoA is an intermediate of which pathway?
Cholesterol biosynthesis and ketogenesis
83
The hormone epinephrine is a ____ and is biosynthesized in the ____.
Catecholamine; adrenal gland
84
Which hormone acts to produce hypoglycemia?
Insulin
85
Which of the following hormones is a steroid?
Aldosterone
86
Which of the following hormones are primarily responsible for the synthesis of fatty acids?
Cortisol
87
What substance controls calcium exchange out of bone?
Parathormone
88
Xanthine is an intermediate in which of the following?
Degradation of purines
89
Which of the following is most likely to result from the genetic inability to break down purines?
Gout;
| Gout can damage not only the big toe, but other bones, too! Check the patient's diet.
90
What is the pyrimidine-purine combination in RNA?
Adenine – uracil
91
Which of the following vitamins is necessary for the biosynthesis of purines?
Folic acid
92
Which amino acid begins the urea cycle?
Arginine
93
Anaerobic metabolism of pyruvate will produce:
Lactate
94
This process begins with the formation of carbamoyl phosphate:
Urea cycle
95
Which of the following is a part of a nucleic acid?
Phosphate
96
Which nitrogenous base is not normally found in DNA?
Uracil
97
In the Watson and Crick model of DNA, the two long polynucleotide chains are held together by which of the following bonds?
Hydrogen
98
Which nitrogenous base is found in DNA but not in RNA?
Thymine
99
Conversion of mRNA genetic information into polypeptides is called:
Translation
100
Which of the following is an intermediate metabolite in the biosynthesis of RNA?
Adenosine triphosphate
101
Reproduction requires
DNA synthesis
102
Which enzyme catalyzes the synthesis of urea?
Arginase
103
Which vitamin is necessary for the proper production of RBCs?
Folacin and Vitamin B12
104
What transaminase coenzyme is derived from vitamin B6?
Pyridoxal phosphate
105
The basic structure of which vitamin contains a metal ion?
Vitamin B12;
| Cobalt is the metal ion (B12 is aka cyanocobalamin).
106
Vitamin E protects cellular and subcellular membranes because it acts as a/an:
Antioxidant
107
Which B-complex vitamin contributes carbon atoms in the formation of a DNA nucleus?
Folic acid
108
The active form of B9 is:
Tetrahydrofolate
109
Which of the following minerals activates the phosphorylation reaction in the metabolism of carbohydrates, proteins and fats?
Magnesium
