Biochem Flashcards
Which of the following statements regarding free radicals is false?
A. Free radicals carry a single, unpaired electron
B. Free radicals are produced as the result of homolytic cleavage of a covalent bond C. A free radical can interact with a molecule to generate a new free radical species D. Free radicals do not occur naturally in the body
E. Biological free radicals are highly unstable molecules
D. Free radicals do not occur naturally in the body
Which of the followings is the most potent free radical?
A. Superoxide radical B. Hydrogen peroxide C. Hydroxyl radical D. Superoxide anion E. Molecular oxygen
Hydroxyl radical
In familial hypercholesterolemia, blood levels of cholesterol are extremely high and severe atherosclerosis develops in childhood. Choose the wrong answer related to these individuals with familial hypercholesterolemia.
A. These individuals have a defective LDL receptor
B. They lack receptor-mediated uptake of cholesterol carried by LDL
C. Cholesterol that is not cleared from the blood accumulates in foam cells and contributes
to the formation of atherosclerotic plaques
D. Endogenous cholesterol synthesis continues
E. Extracellular cholesterol can enter cells to regulate intracellular synthesis
E. Extracellular cholesterol can enter cells to regulate intracellular synthesis
Dysregulation of cholesterol metabolism can lead to cardiovascular disease. Choose the wrong answer related to cholesterol metabolism in human body.
A. Cholesterol can be catabolized by animal cells
B. Excess cholesterol can be removed by excretion
C. Excess cholesterol can be removed by conversion to bile salts
D. Cholesterol is used for the synthesis of membranes
E. Pathological accumulations of cholesterol (plaques) cause atherosclerosis by
obstructing blood vessels
A. Cholesterol can be catabolized by animal cells
When superoxide radical, O2 ̄ ̇, gains a second electron (and two protons) which oxidant substance is formed?
A. Hypochlorous acid (HOCl) B. Nitrous acid (HNO2)
C. Hydrogen peroxide (H2O2) D. Ozone (O3)
E. Dinitrogen trioxide (N2O3)
Hydrogen peroxide (H2O2)
Which of the following biomarkers is of importance indicating the myocardial damage during a subclinical period of several years before the onset of clinical signs of coronary heart disease and death?
A. LDH1 (Lactate dehydrogenase 1) B. Myoglobin
C. Homocysteine
D. cTnI (Cardiac troponin I)
E. CPK (Creatine phosphokinase)
E. CPK (Creatine phosphokinase)
When a hydroxyl radical reacts with a protein, lipid, or DNA molecule, it snatches an electron to itself. What is the product of this reaction?
A. Another radical
B. In case of protein shorter peptides C. In case of DNA nucleotides
D. In case of lipid free fatty acids
E. No radical
D. In case of lipid free fatty acids
Which of the followings is not a free radical? A. Hydroxyl
B. Hypochlorite
C. Nitric oxide
D. Singlet oxygen E. Lipid peroxyl
C. Nitric oxide
