Biochemistry review 1 Flashcards

1
Q

β-pleated sheets are the examples of

A

Secondary structure

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2
Q

A coiled peptide chain held in place by hydrogen bonding between peptide bonds in the same chain is?

A

α-helix

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2
Q

Which of the following is not true about secondary protein structure?

A

The hydrophilic/hydrophobic character of amino acid residues is important to secondary structure

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3
Q

Two chains of amino acids in an insulin molecule are held together by

A

Disulfide bridges

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4
Q

Hemoglobin is a

A

Tetramer

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5
Q

Which of the following is an amino acid?

A

Proline

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5
Q

Number of hydrogen bonds between adenine and thymine?

A

2

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5
Q

Which ratio is constant for DNA?

A

a) A + G / T + C

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5
Q

Which of the following statements is not true about RNA?

A

Thymine is present

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6
Q

Which of the following statements is true?

A

The bases in nucleotides are attached to a pentose sugar moiety by a glycosidic linkage

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6
Q

What is the composition of nucleoside?

A

a base + a sugar

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7
Q

What is the composition of nucleotide?

A

a base + a sugar + phosphate

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8
Q

Group of adjacent nucleotides are joined by

A

Phosphodiester bond

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9
Q

DNA denaturation is measured by absorbance at

A

260nm

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10
Q

Which of the following is false about denaturation?

A

Disruption of phosphodiester linkage

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11
Q

Which of the following nucleotides is not present in DNA?

A

UMP

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12
Q

Which of the following involves carrying genetic information from DNA for protein synthesis?

A

m-RNA

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13
Q

The molecule which acts directly on an enzyme to lower its catalytic rate is

A

Inhibitor

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13
Q

Which of the following enzyme catalyzes the first step of glycolysis?

A

Hexokinase

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13
Q

What is the general mechanism of an enzyme?

A

It acts by reducing the activation energy

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13
Q

Which out of the following statements is true about the regulation of metabolic pathway?

A

Most of the metabolic pathways are regulated

14
Q

What is the general term used for the anaerobic degradation of glucose to obtain energy?

A

Fermentation

15
Q

Whenever the cell’s ATP supply is depleted, which of the following enzyme’s activity is increased?

A

Phosphofructokinase-1

16
Q
  1. Glycolysis converts
A

Glucose into pyruvate

16
Q

When glucose is converted to lactate by anaerobic glycolysis, equivalent number of ATPs derived is?

A

2

17
Q

Which enzyme is involved in the pathway of synthesis of acetyl-coA?

A

Pyruvate dehydrogenase

18
Q

Which of the following is not an important precursor of glucose in animals?

A

Glucose 6-phosphate

19
Q
  1. Gluconeogenesis involves the conversion of
A

Pyruvate to glucose

20
Q

What is the main source of glucose carbons for gluconeogenesis?

A

Alanine

21
Q

Which of the following are the ketone bodies?

A

Acetoacetate and Betahydroxy butyrate

22
Q

The enzyme ‘Thiolase’ catalyzes the conversion of-

A

2 Acetyl co A to Acetoacetyl co A

23
Q

In cystic fibrosis, the pancreatic ducts become obstructed by viscous mucus.
Consequently digestion of which of the following substances would be most

A

Lipids

24
Q

Insulin promotes which of the following ?

A

Transport of glucose in to cells

25
Q

A 15-year-old female has been diagnosed with anorexia nervosa. In this patient breakdown of fatty acids is required to provide energy. Prior to fatty acid oxidation activation of fatty acid takes place in the cytosol. Which of the following is the product of fatty acid activation ?

A

Fatty acyl Co A

26
Q

A fatty acid with 14 carbon atoms will undergo how many cycles of beta oxidation

A

6

27
Q

An obese, 40- year-old woman, who recently underwent gastric bypass surgery, presents with severe vomiting due to rapid intake of large quantities of food, which must be avoided after gastric bypass surgery. She had successfully lost 10 pounds over the last month after the surgery due to mobilization of fat stores to provide acetyl co A and Energy. When Stearic acid (18 carbon atoms long-chain fatty acid) is oxidized, how many Acetyl co A are produced?

A

9

28
Q

A 4 month -old infant presents with a seizure. His mother reports that her infant has been irritable and lethargic over the past several days. The infant is found to have a profoundly low serum glucose and ketone body level. The infant is diagnosed with medium chain acyl co A dehydrogenase deficiency. What is the biochemical basis of infant’s symptoms?

A

Beta oxidation of fatty acid is impaired

29
Q

β- oxidation of long chain fatty acids occurs primarily in which of the following locations?

A

Mitochondria

30
Q

How many carbons are removed from fatty acyl co A in one turn of β-oxidation spiral ?

A

2

31
Q
  1. Folic acid is important for which of the following processes?
A

One carbon metabolism

32
Q

A 20-year-old male presents with hypertension. He has been prescribed a drug that work by inhibiting the synthesis of catecholamines. Which of the following vitamins participates in the synthesis of catecholamines?

A

Vitamin C

33
Q

A bone marrow aspirate of a strictly vegetarian female, confirms the suspicion that she has a pernicious anemia because it showed a greater than normal number of red and white blood cell precursors, most of which were larger than normal. What is the cause of pernicious anemia in this patient?

A

Vitamin B12 deficiency

34
Q

A 3 –year-old girl has been brought for consultation. She is well below the 5th percentile for both height and weight with multiple rachitic deformities of the skeleton to include severe bowing of the tibias bilaterally, pigeon chest and thickened/widened wrists bilaterally. Which of the following vitamins can be recommended as a part of treatment?

A

Vitamin D

35
Q

A 2 –year-old child presented with chronic cough and Bronchitis, growth failure and passage of light-colored, foul-smelling stools. Mother of the child reported that the child was finding it difficult to locate things in the dim light and during night-time. Which of the following vitamins might be deficient in this child?

A

Vitamin A

36
Q

Choose the odd one out-

A

Vitamin C

37
Q

Which of the following cofactors is correctly matched with the vitamins it is derived from?

A

TPP- Vitamin B1

38
Q

Which of the following is not a clinical outcome of niacin deficiency?

A

Night blindness

39
Q

A 70-year-smoker presents with weight loss, blood in the sputum, and fatigue. Imaging shows a nodule in his lung that is diagnosed as cancer by biopsy. It has been proposed that reactive oxygen species may induce mutagenesis
and contribute to the initiation of cancer. Which of the following is an antioxidant vitamin?

A

Folic Acid

40
Q

A 2-year- old child presents with chronic cough, bronchitis, growth failure, chronic diarrhea and growth failure. A deficiency of which of the following vitamins should be considered?

A

Vitamin A

41
Q

Which of the following is the coenzyme form of Thiamine?

A

TPP (Thiamine pyrophosphate)