Chapter 3

_____ is the most abundant organic compound on Earth. Glycogen Cellulose Starch Glucose Lactose

Cellulose

A shortage of phosphorus in the soil would make it especially difficult for a plant to manufacture __________. fatty acids proteins cellulose DNA

DNA The backbone of a nucleic acid consists of alternating sugar and phosphate groups

One difference between DNA and RNA is that __________. DNA is a nucleic acid, and RNA is a protein DNA uses the bases CGAT, whereas RNA uses the bases CGAU DNA uses ribose, whereas RNA uses deoxyribose DNA is single-stranded, whereas RNA is double-stranded

DNA uses the bases CGAT, whereas RNA uses the bases CGAU

All lipids share this characteristic. Lipids don't dissolve in water. They are all made of fatty acids and glycerol. In general, lipids have a low energy content. Lipids are all acidic when mixed with water.

Lipids don't dissolve in water.

Which two statements are true about dehydration synthesis? Monomers or polymers are joined to form longer chains. Polymers are broken down into shorter chains or monomers. An OH group from one component and an H atom from the other form a water molecule. A molecule of water is consumed. Its atoms are added to a bond, putting an OH group on one end and a hydrogen atom on the other.

Monomers or polymers are joined to form longer chains. An OH group from one component and an H atom from the other form a water molecule.

How do prions disrupt the normal function of an organism and cause diseases such as mad cow disease? Prions can convert normally folded proteins into abnormal shapes. Prions are a result of genetic mutations. Prions change the amino acid sequence of their host proteins. Prions are still a mystery. Scientists do not know how prions cause the symptoms of diseases like mad cow disease.

Prions can convert normally folded proteins into abnormal shapes.

Which of these is NOT a lipid? phospholipid cholesterol wax steroids RNA

RNA

Even though lactose intolerance is found in only about 10% of current northern Europeans, researchers studying 7,000-year-old fossil remains of ancient European populations found that most were lactose intolerant. What conclusion might you draw from this evidence? Lactose intolerance is a relatively new mutation. Human populations are not susceptible to natural selection. This change could have come from interbreeding between Neanderthals and modern humans. The mutation for lactose tolerance can arise spontaneously in any population. In Europe, this mutation has rapidly become prevalent through natural selection only within the past 7,000 years.

The mutation for lactose tolerance can arise spontaneously in any population. In Europe, this mutation has rapidly become prevalent through natural selection only within the past 7,000 years.

Glycogen is _____. a source of saturated fat a transport protein that carries oxygen the form in which plants store sugars a polysaccharide found in plant cell walls a polysaccharide found in animals

a polysaccharide found in animals

Through examining DNA from lactose-intolerant individuals, scientists found that __________. a small change in a DNA nucleotide sequence can have a major effect on the production of lactase the enzyme lactase is not encoded by a DNA gene a mutation within the lactase gene is responsible for lactose intolerance males are more likely to be lactose intolerant than females

a small change in a DNA nucleotide sequence can have a major effect on the production of lactase

Protein polymers are made up of ________ monomers. nucleotide amino acid simple sugar

amino acid

Which of these are monomers? cellulose amino acid lactose protein glucose

amino acid glucose

The building blocks of proteins are called __________. amino acids fatty acids DNA and RNA nucleotides

amino acids

A function of cholesterol that does not harm health is its role _____. the most abundant male sex hormone in calcium and phosphate metabolism All of cholesterol's effects cause the body harm. as a component of animal cell membranes as the primary female sex hormone

as a component of animal cell membranes

The large diversity of biological molecules depends on atoms of the element __________. This element can make stable bonds to itself and to atoms of other elements. Without this element, the large macromolecules that make up most of the molecules in living organisms would not be possible. oxygen carbon nitrogen hydrogen

carbon

Hydrocarbons are organic molecules that contain only __________. components found only in crude oil carbon atoms carbon, hydrogen, and oxygen atoms carbon and hydrogen atoms

carbon and hydrogen atoms It's in the name ;)

Plant cell walls consist mainly of __________. chitin peptidoglycan cellulose chlorophyll

cellulose

Which of these is a polysaccharide? galactose sucrose cellulose lactose glucose

cellulose

"Saturated" fats __________. mix easily with water are hydrophilic are composed of at least three fatty acid molecules attached to a glycerol molecule contain only single bonds in their fatty acid tails

contain only single bonds in their fatty acid tails

What is another name for a condensation reaction? water formation dehydration hydrolysis catabolism monomerization

dehydration

DNA has the appearance of a _____. single strand letter U double helix triple helix circle

double helix

All organic molecules contain carbon and hydrogen. What parts of an organic molecule may contain oxygen, nitrogen, or phosphorus? the molecule's skeleton the nonpolar parts of an organic molecule functional groups the hydrophobic parts of an organic molecule

functional groups Functional groups are the parts of biological molecules that often participate in chemical reactions. Different functional groups may contain oxygen, nitrogen, phosphorus, or other elements.

A specific stretch of DNA that codes for the amino acid sequence of a polypeptide is called a __________. gene nucleotide nucleic acid base polypeptide

gene

What is the main sugar used by cells for energy? any polysaccharide glucose aspartame sucrose

glucose

Which of the following pairs of molecules share the same molecular formula but differ in structure? glucose and sucrose glucose and glycogen glucose and fructose DNA and RNA

glucose and fructose

An important characteristic of the double-stranded DNA molecule is that __________. DNA is composed of amino acids linked together by peptide bonds that form a double helix DNA contains four nucleotides: cytosine, uracil, adenine, and guanine phosphodiester bonds are formed between bases in opposing DNA strands to form a double helix hydrogen bonding between base pairs is responsible for formation of a double helix

hydrogen bonding between base pairs is responsible for formation of a double helix

What is the name of the process during which a bond between two monomers is broken? combustion dehydration hydrolysis condensation

hydrolysis

glucose + glucose —> _____ by _____. sucrose + water ... dehydration synthesis lactose + water ... hydrolysis starch + water ... dehydration synthesis maltose + water ... dehydration synthesis cellulose + water ... hydrolysis

maltose + water ... dehydration synthesis

Which of these is a source of lactose? sugar beets potatoes starch milk sugar cane

milk Lactose is the sugar found in milk

Nucleic acid polymers are made up of ________ monomers. nucleotide amino acid simple sugar

nucleotide

DNA is composed of building blocks called _____. nucleic acids Gs nucleotides adenines amino acids

nucleotides

The building blocks of nucleic acid molecules are called __________. nucleotides polysaccharides DNA and RNA amino acids

nucleotides

Which of these is rich in unsaturated fats? a fat that is solid at room temperature olive oil lard butter beef fat

olive oil unsaturated fats are liquid at room temperature

A polypeptide is a long chain of amino acids bonded together by __________. phosphodiester bonds peptide bonds amino acid unique side groups hydration reactions

peptide bonds

Which fat is solid at room temperature?

saturated fat

Carbohydrate polymers are made up of _______ monomers. nucleotide amino acid simple sugar

simple sugar

Glucose plus fructose forms a disaccharide called __________. maltose glycogen starch sucrose

sucrose

Globally, most human adults are lactose intolerant. People with lactose intolerance produce insufficient amounts of __________. View Available Hint(s) the enzyme lactase lactose vitamins saliva

the enzyme lactase Lactase breaks down lactose to simpler sugars that can be digested.

When researchers studied lactose intolerance in people from different geographic regions, they concluded that __________. the percentage of lactose tolerant individuals is roughly the same in all human populations throughout the world there is no correlation between lactose intolerance and DNA mutations in the populations they studied lactose intolerance is a relatively new mutation there may be a selective advantage that favors lactose tolerance in populations that depend on dairy products as a staple in their diet

there may be a selective advantage that favors lactose tolerance in populations that depend on dairy products as a staple in their diet

Which fat is liquid at room temperature?

unsaturated fat

A dehydration reaction is the process in which __________. proteins are broken down to individual amino acids water molecules are formed when polymers are synthesized from monomers water molecules are used as a source of raw material to break down polymers to monomers water molecules are attracted to each other

water molecules are formed when polymers are synthesized from monomers