Which of the following solutions has the greatest concentration of hydrogen ions [H+]

1. gastric juice at pH 2
2. vinegar at pH 3
3. tomato juice at pH 4
4. black coffee at pH 5
5. household bleach at pH 12

gastric juice at pH 2

Nitrogen has 7 protons and 7 neutrons. The atomic mass of nitrogen is

1. 21
2. 1
3. 14
4. 7
5. 18

14

How do isotopes of the same element differ from each other?

1. valence electrons distribution
2. number of electrons
3. number of neutrons
4. amount of radioactivity
5. number of protons

number of neutrons

Carbohydrates normally function in animals as __

1. the functional units of lipids
2. enzymes in the regulation of metabolic processes
3. energy source or energy storage molecules
4. a component of triglycerides
5. sites of protein synthesis

energy source or energy storage molecules

Which of the following characteristics are NOT necessary to being any organism being considered alive?

1. order
2. metabolism
3. growth
4. reproduction
5. brain tissue

brain tissue

a medical scientist is designing an experiment to test the results of a new drug that she hypothesizes will greatly reduce and possibly eliminate the side effects of a cancer treatment. If this experiment is to be set up correctly, sh must

1. divide the patients into two groups and give each group the same amount of new drug
2. divide the patients into two groups and give one group the new drug and give the other group nothing
3. divide the patients into two groups and give one group the new drug and the other group a drug that has no effect
4. divide the patients into two groups and give one group the new drug for one week and the other group a different drug one week

divide the patients into two groups and give one group the new drug and the other group a drug that has no effect

A relatively weak bond between a polar molecule and the weak positive charge on a hydrogen atom is called

1. a covalent bond
2. an ionic bond
3. hydrogen bond
4. a compound bod
5. a bond, james bond

hydrogen bond

The four main classes of organic biological molecules include all of the following EXCEPT:

1. proteins
2. lipids
3. water
4. carbohydrates
5. nucleic acids

water

The three dimensional space where one might find an electron is called

1. a quantum
2. an orbital
3. energy
4. nirvana
5. nuclei

an orbital

What do cohesion, adhesion, and surface tension have in common with reference to water?

1. all are produced by covalent bonding
2. all are properties related to hydrogen bonding
3. all are aspects of a crystalline structure
4. all have to do with ionic interactions
5. all are the results of the structure of the hydrogen atom

all are properties related to hydrogen bonding

Enzyme molecules require specific shape to perform their catalytic function. Which of the following might alter the shape of an enzymatic protein?

1. denaturing the enzyme
2. mixing in a chemical that removes hydrogen bonds
3. a change in salt concentrations or pH
4. heating the protein
5. all of the above

all of the above

Proteins may function as all of the following EXCEPT:

1. enzymes that speed chemical reactions
2. structural materials (microtubules)
3. antibodies for defence
4. membrane transport channels
5. energy currency for cells, in the form of ATP

energy currency for cells, in the form of ATP

In the crystal matrix of ordinary table salt, the sodium and chlorine are held together by

1. atomic bonds
2. covalent bonds
3. ionic bonds
4. hydrogen bonds
5. non polar bonds

ionic bonds

Which of the following are possible consequences of an increase in atmospheric carbon dioxide (CO2)?

1. corals and coral reefs are not able to form their hard skeletons, due to lack of carbonate ions
2. ocean temperatures are dropping
3. clams, mussels, lobster and shrimp cannot be eaten fast enough
4. animals in the oceans cannot get enough oxygen
5. an increase i the oceans white with foam

corals and coral reefs are not able to form their hard skeletons, due to lack of carbonate ions

which of the following effects is produced by the high surface tension of water?

1. lakes don't freeze solid in winter, despite low temperatures
2. a water strider (insect) can walk across the surface of a small pond
3. organisms resist temperature changes, although they give off heat due to chemical reactions
4. the pH of water remains exactly neutral
5. water can act as a solvent

lakes don't freeze solid in winter, despite low temperatures

A triacylglyceride is a form of ___ composed of ___

1. lipid; fatty acids and glucose
2. lipid; fatty acts and glycerol
3. carbohydrate; fatty acids
4. lipid; choloesterol
5. protein; amino acids

lipid; fatty acts and glycerol

One characteristic shared by sucrose, maltose, and lactose is that

1. they are all indigestible by humans
2. they all contain fructose
3. they are all polysaccharides
4. they are all monosaccharides
5. they are all disaccharides

they are all disaccharides

In what polysaccharide form do plants store glucose to be available later as an energy source?

1. protein
2. fatty acids
3. cellulose
4. starch
5. glycogen

starch

Some substances, such as oil and gasoline, will not dissolve in water because

1. oil and gasoline are organic compounds
2. their electrons are so stable that they don't exchange atoms with other molecules
3. their molecules have no charge or partial charges to which water molecules can adhere
4. they are so large
5. none of the above

their molecules have no charge or partial charges to which water molecules can adhere

Which of the following categories includes all of the others in the list

1. disaccharide
2. carbohydrate
3. polysaccharide
4. starch
5. monosaccharide

carbohydrate

In the term "trace element", the adjective trace means that

1. the element can be used to trace atoms through and organism's metabloism
2. the element passes rapidly through the organism
3. the element is required in very small amounts
4. the element enhances health but is not essential for the organism's long-term survival
5. the element is very rare on Earth

the element is required in very small amounts

The specific amino acid sequence in a polypeptide denotes its

1. zero order structure
2. primary structure
3. secondary structure
4. tertiary structure
5. quaternary structure

primary structure

The difference between DNA and RNA is

1. DNA has phosphates in the backbone, RNA does not
2. DNA has a thiamine nucleotide base, while RNA has oracle as a base
3. DNA has ribose sugars in it's backbone, while RNA does not
4. DNA is commonly found only as a double-helix, while RNA is found most commonly as single strands or folded upon itself
5. both "b" and "d"

both "b" and "d"

When excreting in warm temperatures, the human body relies on ___ to absorb excess calories of heat and maintain normal body temperature

1. evaporation
2. condensation
3. respiration
4. transpiration
5. all of the above

evaporation

Which of the following components of a tossed salad will pass through the digestive tract and be digested the least?

1. cellulose (in the lettuce)
2. proteins (in the bacon bits)
3. oil (in the dressing)
4. starch in the croutons
5. sugar (in the dressing)

cellulose (in the lettuce)

If a protein is described as having a quaternary structure, it means that it has

1. only hydrogen bonds
2. multiple protein subunits
3. only covalent and ionic bonds holding it together
4. only ionic bonds
5. only hydrogen and covalent bonds

multiple protein subunits

All of the following are non polar except

1. oils
2. fats
3. CH4
4. H2O
5. gasoline

H2O

Lipids are the only class of macromolecules that contain

1. amino acids
2. nucleic acids
3. fatty acids
4. phosphate groups
5. sugars

fatty acids

When potassium hydroxide (KOH) is added to pure water, it ionizes, releasing hydroxide ions. The resulting solution is

1. acidic
2. basic
3. neutral
4. molar
5. buffer

basic

Carbonic acid and sodium bicarbonate act as buffers in the blood. When a small amount of acid is added to this buffer, the H+ ions are used up as they combine with the bicarbonate ions. When this happens the pH of the blood is designed to

1. become more basic
2. become more acidic
3. change very little
4. is reversible
5. ionizes

change very little

Biological membranes contain bilayers of which of the following lipids?

1. phospholipids
2. oils
3. prostaglandins
4. triglycerides
5. cholesterol

phospholipids

All of the following are examples of monomer: polymer pairings except

1. amino acids: polypeptides
2. monosaccharides: lipids
3. nucleotides: DNA
4. glucose: starch

monosaccharides: lipids

Prokaryotic cells in the genus Sulfolobus are in the Domain Archaea, and are commonly found in the geothermal environments, with an optimum growth temperature of about 80 C. Which of the following features is most likely to allow Archaea to thrive at such temperature?

1. Sulfolobus use the het from their environment to produce ATP
2. Sulfolobus are not adaptable to the changing environmental temperatures
3. Sulfolobus membranes contain high concentrations of saturated lipids
4. Sulfolobus membranes contain high concentrations of unsaturated lipids

Sulfolobus membranes contain high concentrations of saturated lipids

An unsaturated fatty acid has at least one __ as part of its long, non- polar chain.

1. hydroxyl group
2. double bonded pair of carbon atoms
3. triple bonded carbon atom
4. nitrogen atom bonded to carbon

double bonded pair of carbon atoms