physiology ch 2

Which of the following are examples of cations? ANSWER: SO42- HCO3- Cl- HPO42- Ca2+

Ca2+

All of these statements about carbohydrates are true except one. Identify the exception. ANSWER: -Simple sugars include lactose, glucose, and ribose. -Glycogen is important both for energy storage and to provide structure for cells. -Polysaccharides are important both for energy storage and to provide structure to cells. -Cellulose is the most abundant carbohydrate on earth. -Glycogen is a storage polysaccharide made by animal cells.

-Glycogen is important both for energy storage and to provide structure for cells.

Cholesterol is ANSWER: -a precursor to steroid hormones. -a precursor to steroid hormones, a structural component of cell membranes, and a dangerous fat that is absent from a healthy body. -a dangerous fat that is absent from a healthy body. -a structural component of cell membranes. -a precursor to steroid hormones and a structural component of cell membranes.

-a precursor to steroid hormones and a structural component of cell membranes.

Essential amino acids that are used to build proteins ANSWER: -are linked together by ionic chemical bonds in proteins. -exist in twenty six different configurations. -can be used medically for both diagnosis and treatment of diseases. -can only be made by cells within our bodies. -can be derived from the foods we eat and digest.

-can be derived from the foods we eat and digest.

The largest carbohydrate molecules are called polysaccharides because they are composed of ________ molecules bonded together with one another. ANSWER: sugar amino acid nucleotide purine pyrimidine

sugar

The most important energy-transferring compound in cells is a nucleotide known as ANSWER: deoxyribonucleic acid. protein. fructose. adenosine triphosphate. glucose.

adenosine triphosphate.

Atoms in a covalent molecule ANSWER: -share electrons in triple pairs. -share electrons in single pairs. -share electrons in double pairs. -can share electrons in single pairs, double pairs, or triple pairs. -share electrons singly, never in pairs.

-can share electrons in single pairs, double pairs, or triple pairs.

A nucleotide consists of a ANSWER: -five-carbon sugar, a nitrogenous base, and a phosphate group. -five-carbon sugar and an amino acid. -five-carbon sugar and a nitrogenous base. -phosphate group and a nitrogenous base. -five-carbon sugar and phosphate group.

-five-carbon sugar, a nitrogenous base, and a phosphate group.

Cells regulate their level of activity by regulating the amount of proteins present in the cell at any given time, so an up regulation of enzymes would be expected to ANSWER: -increase the rate of reactions catalyzed by the enzymes. -increase the level of productivity of chemical reactions that rely on them. -decrease the level of productivity of chemical reactions that rely on them. -decrease the rate of reactions catalyzed by the enzymes. -both decrease the level of productivity of chemical reactions that rely on them and decrease the rate of reactions catalyzed by the enzymes.

-increase the level of productivity of chemical reactions that rely on them.

In regard to lipids, the term unsaturated refers to ANSWER: -the lack of double bonds between adjacent carbon atoms in a fatty acid. -the ring structure of steroids. -fats, such as butter and lard, which come from animal sources. -the presence of double bonds between adjacent carbon atoms in a fatty acid. -glycerol, which acts as an anchor for joined fatty acids.

-the presence of double bonds between adjacent carbon atoms in a fatty acid.

A molecule referred to as highly soluble is ANSWER: -not very likely to dissolve in water and is called aqueous. -very likely to dissolve in water and is called aqueous. -very likely to dissolve in water. -called aqueous. -not very likely to dissolve in water.

-very likely to dissolve in water and is called aqueous.

Which bases below are purines? 1. adenine 2. cytosine 3. guanine 4. thymine 5. uracil ANSWER: 2, 4, and 5 1 and 3 2 and 3 1, 3, and 5 1 and 2

1 and 3

Which of the following is a way to recognize a carbohydrate by looking at its name only? ANSWER: It always ends in -ase. It ends in -ose It begins with proteo-. It begins with nucleo-. It begins with lipo-.

It ends in -ose

Which group of elements makes up more than 90% of the body's mass? ANSWER: O, C, H O, H, Na Ca, C, O C, Na, K O, Ca, H

O, C, H

Stanley Miller set out to demonstrate an explanation for the origins of organic molecules using a combination of simple organic molecules, heat and periodic burst of electricity through the mixture, ultimately producing what kind of molecules? ANSWER: carbohydrates glycoproteins amino acids nucleic acids lipids

amino acids

The organic molecules known as phospholipids are key components of cell membranes and composed of what monomeric units? ANSWER: fatty acids amino acids nucleotides glycerol both glycerol and fatty acids

both glycerol and fatty acids

Glycosylated molecules are those formed with which group of organic compounds? ANSWER: lipoproteins proteins carbohydrates nucleic acids lipids

carbohydrates

A positively charged ion is called a(n) ANSWER: proton. electron. neutron. cation. anion.

cation.

Each amino acid differs from others in the ANSWER: chemical structure of the R group. number of central carbon atoms. size of the amino group. number of peptide bonds in the molecule. number of carboxyl groups.

chemical structure of the R group.

According to the rules of complementary base pairing, a nucleotide containing the base cytosine would only pair with a nucleotide containing the base ANSWER: uracil. guanine. cytosine. thymine. adenine.

guanine.

The weak interactions between atoms that keep atoms near each other but don't tightly bind them together are called ANSWER: hydrogen bonds. ionic bonds. hydrogen bonds and van der Waals forces. van der Waals forces. van der Waals forces and ionic bonds.

hydrogen bonds and van der Waals forces.

Which of the following is NOT considered an essential element for a living organism? ANSWER: nitrogen oxygen hydrogen carbon mercury

mercury

A free radical is a ANSWER: charged particle. molecule with an extra electron. molecule with an unpaired electron. molecule with an extra neutron. molecule with an extra proton.

molecule with an unpaired electron.

Nucleic acids are polymers of units called ANSWER: nucleotides. fatty acids. ribose. bases. amino acids.

nucleotides.

Polymers are a typical formation of ________ molecules. ANSWER: organic either organic or inorganic inorganic

organic

The chemical bonding behavior of an atom is directly determined by ANSWER: the mass of the atom. the size of the atom. the number of protons. the number and arrangement of electrons. the number of neutrons.

the number and arrangement of electrons.

The most important polar molecule is ________ because it is practically a universal solvent. ANSWER: bicarbonate nucleic acid water sodium chloride magnesium sulfate

water