Question 1

Which of the following best describes homeostasis in the human body?

Accepted Answer

The process by which the body maintains a stable internal environment despite changes in external conditions.

Question 2

A patient is experiencing a rapid drop in blood glucose levels. Which feedback mechanism is most likely to be activated to restore homeostasis?

Accepted Answer

A negative feedback mechanism that stimulates the release of glucagon.

Question 3

Which of the following is NOT one of the four elements that make up the majority of the human body?

Accepted Answer

Calcium

Question 4

Which statement correctly describes the octet rule?

Accepted Answer

Atoms tend to gain, lose, or share electrons to achieve eight electrons in their valence shell.

Question 5

A molecule of water ($$\mathrm{H_2O}) is $$held together by which type of bond, and what type of bond connects multiple water molecules together?

Accepted Answer

Covalent bonds within the molecule; hydrogen bonds between molecules.

Question 6

Which of the following best explains why water is an effective solvent for ionic compounds?

Accepted Answer

Water is a polar molecule, so it can surround and separate ions.

Question 7

A solution has a pH of 4. Which of the following statements is true?

Accepted Answer

The solution is acidic, and $$[\mathrm{H^+}] is $$greater than $$[\mathrm{OH^-}].$$

Question 8

Which of the following best describes the difference between saturated and unsaturated fats?

Accepted Answer

Saturated fats have no double bonds between carbon atoms, while unsaturated fats have one or more double bonds.

Question 9

Which of the following best describes a peptide bond?

Accepted Answer

A covalent bond formed between the amino group of one amino acid and the carboxyl group of another.

Question 10

A protein is exposed to high heat and loses its three-dimensional structure. What is this process called, and what is the likely effect on the protein's function?

Accepted Answer

Denaturation; the protein will likely lose its function.

Question 11

Which of the following best explains how enzymes speed up chemical reactions in the body?

Accepted Answer

They lower the activation energy required for the reaction to proceed.

Question 12

Which of the following is a function of chaperonins in protein structure?

Accepted Answer

They assist in the proper folding of newly synthesized proteins.

Question 13

Which of the following best describes the structure of ATP?

Accepted Answer

A nucleotide with an adenine base, a ribose sugar, and three phosphate groups.

Question 14

Which of the following best explains the alignment of base pairs in DNA?

Accepted Answer

Adenine pairs with thymine, and guanine pairs with cytosine via hydrogen bonds.

Question 15

A patient is diagnosed with a buffer system failure in their blood. What is the most likely consequence?

Accepted Answer

The patient's blood pH will fluctuate more easily, leading to acidosis or alkalosis.

Question 16

Which of the following best describes dehydration synthesis?

Accepted Answer

A chemical reaction in which two molecules are joined by removing a molecule of water.

Question 17

Which of the following is a real-life example of a positive feedback mechanism in the human body?

Accepted Answer

The release of oxytocin during childbirth to intensify uterine contractions.

Question 18

Which of the following best describes the primary structure of a protein?

Accepted Answer

The sequence of amino acids in a polypeptide chain.

Question 19

Which of the following statements about phospholipids is correct?

Accepted Answer

They have hydrophilic heads and hydrophobic tails, forming the bilayer of cell membranes.

Question 20

A scientist is analyzing a solution and finds that it contains a high concentration of $$\mathrm{Na^+}$$ and $$\mathrm{Cl^-}$$ ions. What type of compound is most likely present, and what is its classification?

Accepted Answer

Sodium chloride; a salt.

Anatomy & Physiology: Foundations, Chemistry, and Biochemistry Study Notes

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