Chapter 2 human ap

Matter is composed of elements, which are composed of
atoms

The atomic number of an atom equals the number of ______ and the atomic weight equals the ____.
protons; number of protons plus neutrons

In a covalent bond
atoms share a pair or more of electrons.

In an ionic bond
oppositely charged atoms attract.

Sodium ions and calcium ions are examples of
cations.

When cations and anions meet, they
form ionic bonds.

Water causes ionically-bonded atoms to
dissociate

Carbon can form ___ covalent bonds.
4

Which of the following isotopes has the longest half-life?
Cobalt-60

The ______ uses iodine in a synthesis reaction.
thyroid gland

The isotope most likely to be used to study the thyroid gland is
iodine-131.

Atomic radiation is useful for treating cancer because
radiation harms cancer cells more readily than it does most non-cancer cells.

Exposure to ionizing radiation may
cloud the lens of the eye.
cause cancer.
interfere with normal growth.

Which of the following is not a source of ionizing radiation?
Cholesterol and triglycerides

A CT scan differs from a conventional X-ray image because it is
three-dimensional.

PET imaging follows the emission of
positrons.

The number of protons in an atom of an element always equals its atomic weight.
False

Radioactive isotopes have stable nuclei.
False

Sodium and chloride atoms combine readily because they both lose electrons.
False

The symbol Na+ represents a sodium atom that has lost an electron.
True

Water is an example of a compound.
True

An atom with 10 protons and which has lost 2 electrons is electrically neutral.
False

Chemistry deals with
the composition and changes of substances that make up living as well as non-living matter.

Chemistry is important to the study of physiology because
the foods that we eat are chemicals.
body functions depend on cellular functions that reflect chemical changes.
chemical reactions enable our bodies to extract energy from nutrients.

Which of the following groups of elements accounts for more than 95% of the human body by weight?
Carbon, hydrogen, oxygen, nitrogen

The atoms of different elements have
different atomic numbers.

Isotopes of an element have
the same atomic number but different atomic weights.

The atoms of the isotopes of a particular element vary in the number of
neutrons.

The first electron shell of an atom can hold a maximum of
2 electrons.

The formula H2O refers to
A molecule that contains two hydrogen atoms and one oxygen atom.

A decomposition reaction can be symbolized by
AB → A + B.

A water solution that contains equal numbers of hydrogen ions and hydroxide ions is
neutral.

Electrolytes that release hydrogen ions in water are
acids.

The difference in hydrogen ion concentration between solutions with pH 4 and pH 5 is
tenfold.

A chemical reaction in which parts of different molecules trade positions is a(n)
exchange reaction.

Electrolytes are substances that
ionize in water.

The pH scale measures the
concentration of hydrogen ions in solution.

A person has alkalosis if the blood pH
rises above 7.5.

A complete atom is electrically neutral because
the number of electrons equals the number of protons.

Synthesis reactions are particularly important in the body for
growth of body parts.

On the pH scale
a tenfold difference in hydrogen ion concentration separates each whole number.
the lower the whole number on the scale, the greater the H+ concentration.
pH values above 7 are basic (alkaline).

An acid reacting with a base is
an exchange reaction.

Bases reacting with acids form ________ and water.
salts

The secondary structure of a protein molecule is the result of
hydrogen bonds.

In the body, oxygen
is used during cellular respiration.

Which of the following is characteristic of carbohydrates?
They contain C, H, O, with twice as many hydrogen as oxygen atoms.
They provide much of the energy that the cell requires.
They include sugars and starches.

A simple carbohydrate
has a molecular formula of C6H12O6.

Lipids
are insoluble in water.
include phospholipids, cholesterol, and fats.
contain C, H, and O, but with proportionately less oxygen than in carbohydrates.

Proteins denature when
hydrogen bonds break.

Saturated fats _______ than unsaturated fats.
have more single carbon-carbon bonds

Proteins
are structural materials.
can function as enzymes.
contain C, H, O, and N, and sometimes S.

An enzyme is a ____.
protein that speeds up chemical reactions without being changed or depleted

The parts of a protein that change when it denatures are
the secondary and tertiary structures.

DNA
stores genetic information, including instructions for enzymes that synthesize fats and carbohydrates.

Nucleic acids are
composed of building blocks called nucleotides.

The informational content of DNA and RNA is in the nitrogenous bases because
the bases are of several types and therefore can form a code sequence.

Nucleic acids include
RNA and DNA.

DNA and RNA differ in that
DNA holds genetic information and RNA uses that information to synthesize protein.

The type of organic molecule that can replicate is a
nucleic acid.

Conformation is
the three-dimensional shape of a molecule, such as a protein.

An organic compound always contains
carbon and hydrogen.

Which of these is not a monosaccharide?
Sucrose

Glycogen is stored in the liver and ______.
skeletal muscles

A triglyceride consists of
3 fatty acids and 1 glycerol.

A biomarker is
a body chemical associated with a particular disease or exposure to a toxin.

An example of a biomarker is
cholesterol.

A biomarker test for cancer should ideally be
inexpensive.
easy to perform.
specific.

Chemistry is the study of the composition of matter and how matter changes.
True

At atom that has gained or lost electrons is called an ion.
True

A substance that releases hydrogen ions in water is a base.
False

A strong acid reacting with a strong base produces a salt.
True

Chemically inert atoms always have their outermost electron shell full.
True

An acid is an electrolyte that releases hydroxide ions (OH-) in water.
False

A base is an electrolyte that releases ions that combine with hydrogen ions.
True

An electrolyte ionizes in water.
True

A person with alkalosis has a blood pH less than 7.3.
False