Mastering Biology Ch. 3
How many different amino acids do cells use to build proteins?
20
If a strand of DNA has the nitrogen base sequence 5'-ATTTGC-3', what will be the sequence of the matching strand?
3'-TAAACG-5'
If a DNA double helix is 100 nucleotide pairs long and contains 25 adenine bases, how many guanine bases does it contain?
75
Which one of the following molecules is a carbohydrate?
C60H100O50
How does a protein's quaternary structure differ from other levels of protein structure?
It involves two or more polypeptide chains.
Which of these is NOT a lipid?
RNA
A peptide bond is shown below as it forms. The bond forms through _____.
a dehydration reaction between the amino group of one amino acid and the carboxyl group of a second amino acid
Protein molecules are polymers of _____.
amino acid molecules
Proteins are polymers of _____.
amino acids
To what does the term polypeptide specifically refer?
amino acids linked by dehydration synthesis
Lipids differ from other large biological molecules in that they _____.
are not truly polymers
A function of cholesterol that does not harm health is its role _____.
as a component of animal cell membranes
Carbohydrates are mainly used in our bodies _____.
as fuel
Which of the following foods would contain the most starch?
carrots
Plant cell walls consist mainly of _____.
cellulose
Which of these is a polysaccharide?
cellulose
_____ is the most abundant organic compound on Earth.
cellulose
The peptide bond is _____.
covalent bond
DNA nucleotides are composed of _____.
deoxyribose sugars, which are bonded to a phosphate group and a nitrogenous base
What is the main sugar used by cells for energy?
glucose
A polysaccharide that we use for storing energy in our muscles and livers is _____.
glycogen
a polysaccharide found in animals
glycogen
The secondary structure of a protein results from _____.
hydrogen bonds
The two strands of a DNA double helix are held together by _____ that form between pairs of nitrogenous bases.
hydrogen bonds
The oil and vinegar in your salad dressing remain separate from one another due to the _____ properties of the oil.
hydrophobic
Which is the correct term for compounds that do not mix with water?
hydrophobic
Defensive proteins are manufactured by the _____ system.
immune
Cholesterol belongs to which class of molecules?
lipids
glucose + glucose —> _____ by _____.
maltose + water ... dehydration synthesis
Which of these is a source of lactose?
milk
The characteristic that all lipids have in common is that _____.
none of them dissolves in water
Which of these is rich in unsaturated fats?
olive oil
Which of these does NOT contain a structural protein?
ovalbumin
What type of bond joins the monomers in a protein's primary structure?
peptide
Tertiary structure is NOT directly dependent on _____.
peptide bonds
A nucleotide is composed of a(n) _____.
phosphate group, a nitrogen-containing base, and a five-carbon sugar
The lipids that form the main structural component of cell membranes are _____.
phospholipids
Cellulose is a _____ made of many _____.
polymer ... glucose molecules
A molecule with the formula C6H12O6 is _____.
possibly glucose or fructose
The alpha helix and pleated sheet represent which level of protein structure?
secondary structure
The overall three-dimensional shape of a single polypeptide is called the _____.
tertiary structure
The "primary structure" of a protein refers to _____.
the number and sequence of amino acids
