Chapter 2

In plasma, a typical body fluid, protein floating around would be considered to be which of the following?

a solute, specifically both a colloid and an electrolyte

What is the classification of a solution with a pH of 8.3?

alkaline solution

The presence of what group differentiates most amino acids from each other?

an R group

Which organic molecules form the major structural materials of the body?

proteins

Which of the following is the major positive ion outside cells? potassium magnesium hydrogen sodium

sodium

Cortisol is a type of lipid hormone. Which type of lipid would cortisol be classified as?

steroid

Amino acids joining together to make a peptide is a good example of a(n) ________ reaction.

synthesis

True or False: Covalent bonds are generally less stable than ionic bonds.

False

True or False: Lipids are a poor source of stored energy

False

What is the difference between kinetic and potential energy?

Kinetic energy is energy in action, while potential energy is stored energy.

Why can dehydration be such a life-threating event?

It significantly alters the ratio of body water (solvent) to dissolved substances (solutes), such as sodium ions.

Which of the following elements is necessary for proper conduction of nervous impulses? -I -Na -Fe -P

Na

What explains the negative charge on the oxygen atom within the water molecule?

Oxygen atoms have a stronger pull on the electrons shared within a covalent bond formed between oxygen and hydrogen.

Blood loss due to a moderate hemorrhage has several adverse effects on patient wellbeing. Why would administering IV fluids alone not be sufficient to return a patient to health?

Oxygen-carrying red blood cells lost along with the fluid component must also be replaced.

Which of the following is NOT one of the three basic steps involved in enzyme activity? -The enzyme's active site binds to the substrate(s) on which it acts, temporarily forming an enzyme-substrate complex. -The enzyme releases the product(s) of the reaction. -The substrate absorbs chemical energy from the enzyme after binding to its active site. -The enzyme-substrate complex undergoes internal rearrangements that form the product(s).

The substrate absorbs chemical energy from the enzyme after binding to its active site.

True or False: ATP is an unstable, high-energy molecule that provides body cells with a form of energy that is immediately usable.

True

True or False: Buffers resist abrupt and large changes in the pH of the body by releasing or binding ions.

True

Foods are broken down into their building blocks by adding water. This would be an example of which characteristic of water?

Water acts as a reactant.

Water acts to dissolve molecules in the body. How does water dissolve the salt (NaCl) in your mouth from a salty pretzel?

Water acts as a solvent because the partial negative charge on the oxygen in water attracts sodium, while the partial positive charge on hydrogen attracts chloride. This results in the separation of sodium from chloride, thus breaking the ionic bond.

All amino acids (such as the four represented in the figure) contain ______.

an amine group and a carboxyl group

All amino acids, such as the four represented in the figure, contain __________.

an amine group and an acid group

What holds the sodium and chloride ions together in a chemical bond

an electrical attraction between opposite charges

What function group pairing allows amino acids to bond together to form polypeptides?

bonding of amine group to acid group

Which four elements comprise approximately 96% of our body weight?

carbon, oxygen, hydrogen, and nitrogen

Select which reactions will usually be irreversible regarding chemical equilibrium in human bodies. -glucose to CO2 and H2O -ADP + Pi to make ATP -glucose molecules joined to make glycogen -H2O + CO2 to make H2CO3

glucose to CO2 and H2O

Carbohydrates are stored in the liver and muscles in the form of ________.

glycogen

What type of bond is formed between the oxygen atom of one water molecule and the hydrogen atom of another water molecule?

hydrogen bond

Which of the following is NOT one of the three major types of chemical reactions? synthesis exchange decomposition hyperbolic

hyperbolic

The pH scale ________.

is based on the concentration of hydrogen ions in a solution

Which pH is more acidic, a pH of 3, a pH of 7, or a pH of 9?

pH of 3

A chemical reaction in which bonds are broken is usually associated with ________.

the release of energy

What is the most significant factor in the formation of a covalent bond?

the sharing of electron pairs between two atoms

What are the two fundamental roles of DNA?

to provide the instructions for protein synthesis, and replicate itself before cell division