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