Biochemistry Practice Test 12
Biochemistry NCLEX Practice Test
Biochemistry is a key topic within the NCLEX test plan, located under Nursing Science → Clinical Foundations → Biochemistry. This section links metabolic processes to nutrition, medication action, and laboratory interpretation in nursing care. Each test contains 50 questions designed to mirror the difficulty and variety of the real exam.
This is the 12th part of the Biochemistry series. To explore all practice tests under this topic, use the “Back to Main Topic” button at the end of the page.
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In the Biochemistry Study Cards section, shared by real NCLEX candidates, you’ll find concise summaries and high-yield insights related to the most tested concepts. It’s a perfect space to reinforce challenging topics and sharpen your recall through quick, focused repetitions. Short, powerful, and repeatable!
Biochemistry Practice Test 12
What is the process of converting glucose to pyruvate called?
- Glycolysis
- Krebs cycle
- Electron transport chain
- Photosynthesis
Explanation: Answer reason: That glucose-to-pyruvate pathway is glycolysis and does not require mitochondria or oxygen to proceed. The Krebs cycle occurs after pyruvate is converted to acetyl-CoA and runs in the mitochondrial matrix, so it is downstream of this step. The electron transport chain uses NADH/FADH2 to drive oxidative phosphorylation on the inner mitochondrial membrane, and photosynthesis is a plant process unrelated to human glucose catabolism.
What is the primary product of the "Light-Independent" reactions (Calvin Cycle) in photosynthesis?
- Oxygen
- ATP
- Glucose (G3P)
- NADPH
Explanation: Answer reason: Its direct output is the 3-carbon sugar glyceraldehyde-3-phosphate (G3P), which can be converted into glucose and other sugars. Oxygen is generated during the light-dependent splitting of water, not during the Calvin cycle. ATP and NADPH are primarily consumed (not produced) in the light-independent reactions to drive carbon fixation and reduction.
In DNA replication, which enzyme is responsible for "unzipping" the double helix?
- DNA Polymerase
- Primase
- Helicase
- Ligase
Explanation: Answer reason: Helicase performs this strand-separation (“unwinding/unzipping”) step by moving along DNA and opening the double helix ahead of the replication machinery. DNA polymerase instead synthesizes new DNA, primase lays down RNA primers to start synthesis, and ligase seals nicks between fragments. Therefore, the enzyme responsible for unzipping is the one that unwinds the helix at the fork.
Which type of bond holds the two strands of DNA together?
- Ionic bond
- Covalent bond
- Hydrogen bond
- Peptide bond
Explanation: Answer reason: Adenine pairs with thymine via two hydrogen bonds, and guanine pairs with cytosine via three, providing specificity while allowing strand separation during replication and transcription. Covalent bonds instead form the sugar-phosphate backbone within each strand (phosphodiester linkages), not between strands. Ionic and peptide bonds are not the primary interactions responsible for base pairing in DNA structure.
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