Homework | Chemicals of Life

A solution that contains more hydrogen ions (H+) than hydroxide ions (OH-) is _____.

Acidic solution

The presence of water in our bodies allows us to _____.

All of these choices are correct

An enzyme can only bind one substrate at a time.

False

Adenosine triphosphate, or ATP, belongs to which group of substances?

Nucleic acids

Ionic Bonds 1. When an atom gains or loses electrons, an ion is formed. True 2. Cations and anions share electrons to form an ionic bond. False 3. Cations and anions connect to each other because of the force of attraction between opposite charges. True 4. When a neutral atom loses an electron, it becomes a cation. True 5. When a neutral atom loses an electron, it becomes an anion. False

True False True True False

Which of the following is a synthesis reaction?

Two amino acids are bonded together to form a dipeptide.

When the energy from a single ATP molecule is used, the resulting phosphate group (Pi) and _____ will be reunited using chemical energy derived from the breakdown of nutrients such as glucose.

adenosine diphosphate

Which term describes a solution that contains more hydroxide ions than hydrogen ions?

basic

The action of an enzyme in speeding up a chemical reaction is referred to as _____.

catalysis

As hydrogen ion concentration increases, the pH number _____.

decreases

Large carbohydrates are formed from smaller units called _____.

monosaccharides

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

neutrons

The building blocks of nucleic acids are _____, which consist of a phosphate group, a five-carbon sugar, and a nitrogenous base.

nucleotides

With rare exceptions, enzymes belong to the major organic substance group called _____.

proteins

Inorganic salts are involved in many important physiological processes, with the exception of _____.

serving as energy carriers

Salts ionize in aqueous solutions to release charged, inorganic atoms or substances called ions. In biological systems, the most common of these functionally important ions are

sodium, calcium, potassium, and phosphate.

Which of the following binds to the active site of an enzyme?

substrate

ATP contains _____ high energy bonds that can be used by enzymes. These bonds are located in the molecule's _____ .

two; phosphate groups

Chemical Reactions Synthesis Decomposition Reversible Exchange

A new product is chemically created from two or more reactants. A larger reactant is chemically broken down into two or more products. The reaction can proceed from product to reactants or reactants to product. Portions of two or more molecules trade places.

Atoms will fill up the shells around them, one shell at a time, starting with the innermost shell. The first shell can hold 2 electrons, the second and third can each hold 8 electrons. The most common elements used in organic compounds, H, C, N, and O do not have enough electrons to fill up the first two shells, which would require 10 electrons to fill. They have 1, 6, 7 and 8 electrons, respectively. The closer an atom's electron configuration is to having fully complete shells, the more readily it will give or take electrons. The following atoms are described in terms of a nucleus and its shells, in order, from innermost to outermost: nucleus (N) / electrons in shell 1 / electrons in shell 2 / electrons in shell 3 Atom A: N / 2 / 8 / 3 Atom B: N / 2 / 7 Atom C: N / 2 / 8 / 5 Atom D: N / 2 / 8 / 1 Which of the following statements represents the most likely interaction among these atoms?

Atom B will most likely take an electron from Atom D, which will most likely give away an electron.

Organic Substances in the Human Body Composed mostly of carbon, hydrogen, and oxygen in approximately 1:2:1 proportions. Mostly composed of carbon and hydrogen, with few oxygen atoms. Always contain carbon, hydrogen, oxygen, and nitrogen. Poorly soluble in water. Composed of repeats of N-C-C that are linked by peptide bonds and carry one of 20 side groups. As an example, enzymes control chemical reactions.

Carbohydrates Lipids Proteins Lipids Proteins Proteins

An enzyme speeds up a chemical reaction in the cell, but can only be used once.

False

pH Scale 1. The pH scale is a measure of oxygen concentration in a solution. False 2. The pH scale indicates the concentration of H+ in a solution. True 3. The pH scale ranges from 0 to 14. True 4. Neutral solutions have a pH of 7. True 5. Solutions with a pH greater than 7 are acidic. False 6. Buffers help maintain pH homeostasis. True

False True True True False True

Which of the following statements is true?

H2O is composed of two hydrogen atom and one oxygen atom.

Which of the following nitrogen bases is found in RNA but not DNA?

Uracil

In general, substances that do not contain carbon are _____ substances, while substances that do contain carbon are _____ substances.

inorganic; organic