Chapter 2 Review

The sugar in DNA is___________while the sugar in RNA is_________

Deoxyribose, Ribose

Proteins

Has several different levels of folding Structural and biological catalyst macromolecules of amino acids with various functions

Besides replicating before cell division, the other fundamental role of DNA is

Instructions to make protein

How do ions form ionic bonds?

Ions of opposite electrical charges are attracted to each other to balance the charges.

Which statement best describes energy?

It does not have mass or occupy space.

If an atom has 10 electrons in its valence shell, how will it interact with atoms of a different element?

It will give away 2 valence electrons to other atoms.

Which of the following is NOT true about matter?

Liquids have neither a definite shape nor a definite volume.

Lipids

Make up the majority of cell membrane structure Not soluble in water Concentrated energy made up of hydrocarbon chains or rings

Carbohydrates

Monosaccharide is the monomer Commonly used source of energy with the ratio 1 carbon-2 hydrogen-1 oxygen

Steroids

Most physiologically important example is cholesterol Fats that are the basis for some hormones

The nucleus of an atom is the location of which kinds of subatomic particles?

Neutrons and protons

Antibodies, enzymes, and some hormones are all examples of which class of organic compounds?

Proteins

Which of the following is NOT true about proteins?

Proteins account for about 10 percent of the organic matter in the body.

ATP is a modified nucleotide used for cellular energy that contains the sugar

Ribose

Solution A has a pH of 4. Solution B has a pH of 13. Identify the correct statement.

Solution A is more acidic than solution B (Solution A has more hydrogen ions).

Which of the following is true of polar covalent bonds?

The electrons are shared unequally.

What occurs when acid is added to a solution with a pH of 7?

The pH drops below 7.

Triglycerides

Three fatty acids attached to one glycerol molecule At least one fatty acid chain, typically saturated with hydrogens

In DNA, adenine pairs with ______ but in RNA, adenine pairs with ______.

Thymine,Uracil

A compound is defined as __________.

a molecule composed of two or more elements

Nucleotides, the building blocks of nucleic acids, are made up of __________.

a nitrogen-containing base, a pentose sugar, and a phosphate molecule

Nuc-

center

A bond that occurs when electrons are shared is a __________ bond.

covalent

Many chemical reactions, called ________ synthesis reactions, occurs by removing water.

dehydration

The term "__________" refers to a unique substance that cannot be decomposed or broken down into simpler substances.

element

Substances that cannot be broken down into smaller compounds are __________.

elements

In a cell membrane, the polar heads of phospholipids are in contact with water-based solutions, meaning they are

hydrophilic

In a cell membrane, the fatty acid tails of phospholipids are hidden inside the membrane away from water, meaning they are

hydrophobic

Covalent bonds:

involve the sharing of one to three pairs of electrons.

All matter consists of elements. The greatest part of living matter is organized using only four elements. Which of the following elements does NOT make up the bulk of living matter?

iron

If neutral atoms become positive ions, they __________.

lose electrons

poly-

many

When you ride a bike, the body converts chemical energy to __________ energy to move the limbs necessary to turn the pedals.

mechanical

The only electrons that are important when considering bonding behavior are those in the __________ shell. This shell is called the __________ shell.

outermost; valence

The four most abundant elements in all life forms on Earth are __________.

oxygen, carbon, hydrogen, and nitrogen

What is the main type of lipid found in cellular membranes?

phospholipids

A molecule of water (H2O) is formed by what type of bond?

polar covalent bonds

Protons carry a __________ charge and electrons carry a __________ charge.

positive, negative

What subatomic particle or particles have a mass of 1, a charge of +1, and are located in the nucleus of an atom?

proton

The atomic number identifies the element and refers to the number of __________.

protons

The function of ATP is to __________.

provide a form of chemical energy that is usable by all body cells

Which of these is an example of kinetic energy?

skeletal muscles contracting as a person lifts weights

When an ionic bond forms, which part(s) of the atoms are directly involved?

the outermost electrons

Calcium's atomic number is 20. It forms ions with 18 electrons. What is the electrical charge of a calcium ion?

+2

What is the number of neutrons in an atom with atomic mass of 35, three energy levels, and 7 valence electrons?

18

-phil

"attraction" or "loving"

-phob

"sensitivity to" or "fear"

Which of the following is NOT true of carbohydrates?

A glucose molecule is a polysaccharide stored by the liver.

What is the name of the high energy compound the body uses to do work?

ATP

Nucleic Acids

ATP is a modified version Genetic information comprising a sugar-phosphate backbone and complementary base pairing

If the DNA molecule resembles a twisted ladder, which chemical units form the sides of the ladder?

Alternating deoxyribose sugar and phosphate molecules

Which of these statements best describes an element?

An element is composed of identical atoms.

In a covalent bond,

Atoms share one or more pairs of electrons.

What is the most accurate description of C6H12O6?

C6H12O6 is a compound.

Phospholipids

Charged "head" region with an uncharged "tail" region Bilayer forms selectively permeable cell membrane Fats that contain phosphate groups

Guanine always pairs with _____.

Cytosine

Glycogen → glucose is an example of which pattern of chemical reaction?

Decomposition reaction

What bonds are formed when electrons are shared equally?

Nonpolar covalent bonds

The center organelle of a cell is called the

Nucleus

__________ changes do not alter the basic nature of a substance.

Physical

While a dipeptide has two amino acids a __________ has many.

Polypeptide

What organic molecule provides an immediate source of chemical energy within all cells?

adenosine triphosphate

Proteins are made up of many __________.

amino acid molecules

What is an ion?

an atom that has either gained or lost electron(s)

Chemicals in the body that help control the body's pH are called __________.

buffers

Choose the best description for the term molecule.

two or more atoms combined chemically

Which nitrogen-containing base is found only in RNA?

uracil

hydr-

water

All of the following are true about the importance of water, an inorganic compound, in the body EXCEPT that __________.

water is an excellent solvent because it is nonpolar