Biochemistry and Atomic Structure Review

A set of fill-in-the-blank flashcards covering isotopes, atomic structure, bonding, solutions, acids and bases, buffering, and key biochemistry concepts from the lecture.

Isotopes exist because on the periodic table, the mass number indicates the most common type found in nature or man-made; however, changing the mass number indicates a difference in __.

neutrons

Radioisotopes can be radioactive and are useful for diagnostic imaging because of __.

radioactivity

Atomic number is the number of __ in an atom.

protons

Mass number equals the total number of and in the nucleus.

protons and neutrons

In an ion, the number of __ changes; protons never change.

electrons

A neutral sodium atom has 11 electrons; if it becomes a sodium ion (Na+), its electron count becomes __.

10

Protons never change; they remain at __.

11

An ionic bond forms when electrons are transferred, producing a and a ion.

cation; anion

In a covalent bond, atoms __ electrons to achieve stability.

share

In CH4, carbon shares electrons with hydrogen to achieve a full outer shell of __ electrons.

eight

Water is a classic example of a __ molecule due to unequal electron sharing between O and H.

polar

Hydrogen bonds are __ forces between molecules.

attractive forces

Water has a high __ capacity, helping stabilize body temperature.

heat

Water has a high heat of __, enabling cooling through evaporation.

vaporization

The polar solvent properties of water allow it to dissociate salts into and .

cations; anions

Hydrolysis means to __ with water to split a molecule.

split apart

Dehydration synthesis means to __ water to build a larger molecule.

remove

Surfactant is secreted by type II alveolar cells and reduces the surface __ of water in alveoli.

tension

Surfactant begins production around __ weeks of gestation.

28

A buffer resists abrupt changes in pH; a major buffering agent in the body is __.

hemoglobin

In the bicarbonate buffering system, carbonic acid dissociates into H+ and __.

bicarbonate

Normal blood pH is approximately __ (7.35–7.45).

7.35 to 7.45

On the pH scale, increasing numbers indicate more __.

basic

On the pH scale, decreasing numbers indicate more __.

acidic

The stomach's pH is around __.

2

The body's main energy currency is __.

ATP

Enzymes are __ that speed up chemical reactions without being used up.

catalysts

Exergonic reactions __ energy.

release

Catabolic reactions break things down; anabolic reactions __.

build up

Increasing temperature, reactant concentration, and smaller particle size all increase the rate of chemical reactions by increasing the number of __ between reactant particles.

collisions

Gatorade replenishes electrolytes such as potassium (K+), chloride (Cl-), and __.

magnesium

Ions that carry electrical impulses are called __.

electrolytes

A lack of ionic balance in muscles can lead to fatigue and cramping due to disrupted __ balance.

electrolyte balance

Oxygen has a valence of __ electrons.

6

If a covalent bond has an unequal sharing of electrons, it is a __ covalent bond.

polar

The octet rule states that most atoms are most stable with a full outer shell of __ electrons.

eight

Water is known as the universal __ in the body.

solvent

In a solution, the water-based component is the __, and the dissolved substance is the __.

solvent; solute

Protons are found in the __, have a __ charge, and contribute to the atomic number.

nucleus; positive

Neutrons are located in the __ and have a __ charge.

nucleus; neutral

Electrons are found in __ shells around the nucleus and have a __ charge.

electron; negative

A cation forms when an atom __ electrons, resulting in a __ charge.

loses; positive

An anion forms when an atom __ electrons, resulting in a __ charge.

gains; negative

Water's polarity allows it to attract other polar molecules and ions, making it an excellent __.

solvent

When blood pH drops (becomes too acidic), the bicarbonate buffering system consumes excess __ ions.

H+

When blood pH rises (becomes too basic), the bicarbonate buffering system releases __ ions.

H+

ATP releases energy when its __ phosphate bond is broken, forming ADP and an inorganic phosphate.

terminal

Enzymes function by binding to specific __ at their active site, thereby lowering the activation energy of a reaction.

substrates