Chapter 3 biology
The four nitrogenous bases present in DNA are
A,G,T,C
methyl group
-CH3, nonpolar
Carbonyl group
-CO
Phosphate group
-PO 4 2-
sulfate group
-SO 4-
How many covalent bonds can a carbon atom form with other atoms?
4
pentose sugars have ___ carbon atoms, and hexose sugars have _____ carbon atoms
5,6
Carboxyl group
A -COOH group, found in organic acids.
Which of the following accurately describes the chemical structure of a typical amino acid found in a protein?
A central carbon atom is bound to an amino group, carboxyl group, a side chain, and a hydrogen atom.
A glycosidic bond or glycosidic linkage is
A glycosidic bond or glycosidic linkage is a type of covalent bond that joins a carbohydrate (sugar) molecule to another group, which may or may not be another carbohydrate
Why do phospholipids arrange into bilayers? Select all that apply.
The bilayer is the most energetically favorable arrangement in aqueous solution. The hydrophilic ends attract water while the hydrophobic ends exclude water.
What are the functions of fats in living organisms ?
energy storage, support cushion for organs and insulation
When fatty acids are linked to glycerol, a type of covalent bond called a(n) Blank 1 of 1 bond is formed.
ester
What type of bond joins fatty acids and glycerol in a fat molecule?
ester bond
The elements of a polypeptide's secondary structure , the a helix β pleated sheets are stabilized by______bonds.
hydrogen
Two strands of DNA are bound together by_______ bonds to form the double helix
hydrogen
What type of bond is responsible for the base pairing between two strands of DNA in the double helix?
hydrogen
the elements of a polypeptide's secondary structure , the a helix and B pleated sheets are Stabilized by _______ bonds
hydrogen
The C=C double bonds in fatty acids introduce a(n) ______into the linear shape of the fatty acid chain.
kink, bend , angle
In an aqueous environment, phospholipids form lipid ___________ with hydrophobic ends facing the interior because this is energetically most favorable for these molecules.
lipid bilayer
Unsaturated fats have_______melting points than saturated fats
lower
Polysaccharide
many monomers
The part of this phospholipid that is indicated with the arrow is:
nonpolar hydrophobic
The building blocks of nucleic acids are monomers called
nucleotides
The primary structure
of a protein is the amino acid sequence of its polypeptide.; the linear sequence of amino acids
monosaccharides
one monomer
A protein whose highest level of structure is tertiary structure contains
one polypeptide folded into its three-dimensional structure
What are the three basic components of a nucleotide?
phosphate group nitrogen-containing base sugar
carbohydates polymers are called
polysaccaharides
The chemical structure of all______ consists of four fused rings of carbon atoms with one or more polar hydroxyl groups attached to the ring structure
steroids
The major classes of lipids
steroids triglycerides phospholipids waxes
What is the secondary structure of a protein?
the repeating patterns of folding between regions
what is the function of waxes
they prevent water loss
Carbon has four electrons in its outer shell
Carbon can form four covalent bonds with other atoms
Carbon atoms can form polar and non-polar bonds
Carbon serves as the backbone for a variety of biologically important organic molecules
carbon atoms can form polar and non-polar bonds
Carbon serves as the backbone for a variety of biologically important organic molecules
What are the three major structural components of an amino acid
Carboxyl group amino group side chain (R)
all the parts that make up the polar hydrophilic region of a phospholipid molecule.
Charged nitrogen-containing region Phosphate group Glycerol backbone
Carbohydrates
Choice, Have the general formula Cn(H2O)n, where n is a whole number
All steriod hormones are derived from ______
Cholesterol
__________ is a precursor of all steriod hormones
Cholesterol
Proteins
Composed of smaller subunits called amino acids
Nucleic acids
Composed of smaller subunits called nucleotides
What four nitrogenous bases are found in DNA
Cytosine Thymine Guanine Adenine
The most common hexose is
D-glucose
What macromolecules is used for the storage of genetic information in cells?
DNA
What type(s) of sugar forms the backbone of DNA molecules?
Deoxyribose
Which of the following are pentoses ?
Deoxyribose and Ribose
How does the presence of a double bond influence the shape of a fatty acid?
Double bonds between carbon molecules introduce kinks in the otherwise linear structure of fatty acids.
How can fats provide protection for mammals in cold weather?
Fats under the skin can provide insulation to protect against cold.
What feature of fats allow them to store high levels of energy?
Fatty acids contain long chains of C-H bonds
Which of the following describes the chemical structure of steroids?
Four fused rings of carbon with one or more attached hydroxyl groups
which of the following nitrogenous bases are purines?
Guanine Adenine
What type of bond is responsible for the formation of a helix and B pleated sheets
Hydrogen bond
What types of bonds are broken when a proteins is denatured?
Ionic bonds Disulfide bonds Hydrogen bonds
What happens when protein is denatured?
Its three-dimensional structure is disrupted
The length of a carbon-carbon bond is short
Molecules with carbon bonds can function across range of temperatures
Smallest to largest carbohydrates
Monosaccarhids disaccharides polysaccharide
Why are most organisms unable to use cellulose for energy production?
Most organisms do not have enzymes that can break down cellulose.
Which of the following atoms form polar covalent bonds with carbon?
Nitrogen Oxygen
Atoms form POLAR COVALENT bonds with carbon
Nitrogen Oxygen
Lipids
Nonpolar molecules that are primarily composed of C and H, with some O
What are the monomers of nucleic acids ?
Nucleotides
Hydroxly group
OH-
In what organisms are starch and glycogen found?
Starch is found in plants and glycogen is found in animals.
Starch and glycogen are used for ______ in living cells.
Storing energy
The three basic components of a nucleotide are pentose_____, an ____ group , and a ring of carbon and ____ atoms called a base
Sugar, phosphate ,and nitrogen
What functional group is involved in disulfide bridges
Sulfhydryl
What level of protein organizations refers to the three-dimensional shape of a polypeptide that includes all secondary structures and interactions between side chains
Tertiary structure
proteins are made up of chains of ______ acids
amino
How can amino acid side chains affect the structure and function of a protein
amino acid side chains play a role in protein folding amino acid side chains are involved in catalysis at the active site of enzymes
What are the monomers found in proteins?
amino acids
Saturated fats are typically found in_______ , and unsaturated fats are more commonly found in _____
animals , plants
Macromolecules
are large molecules made from smaller organic molecules.
Monomers
are small molecules that are linked together to form polymers such as proteins, polysaccharides, and nucleic acids.
Cn(H2O)n is the general chemical formula of a:
carbohydrate
monosaccarides
carbohydrate monomers are known as
What are macromolecules?
carbohydrates, lipids, proteins, nucleic acids Large molecules that are formed by joining smaller molecules together
The amount of energy a fat contains is determined by how many bonds it has between Blank 1 of 2 atoms and Blank 2 of 2 atoms.
carbon , hydrogen
three chemical elements that are found in all carbohydrates are
carbon , hydrogen, and oxygen
What are the three atoms found in all carbohydrates ?
carbon , oxygen and hydrogen
Which of following atoms form non-polar covalent bonds with carbon
carbon and hydrogen
Isomers are molecules that have the same ______ but different ______ and characteristics.
chemical formula; structures
Orgainic Molecules contains
contain Carbon Hydrogen Oxygen Nitrogen
the process by which monomers combine to form polymers is called
dehydration
Proteins are made by_______ reactions, in which water is removed as amino acids are linked together to form polypeptides.
dehydration reaction
What process is responsible for linking amino acids together to form polypeptides?
dehydration reactions
Structural isomers
different arrangement of same elements
A DNA molecule consists of two strands coiled around each other to form a structure called a(n
double helix
Which sugar monomer forms the polysaccharides starch, cellulose, and glycogen?
glucose
Starch, glycogen, and cellulose are all polymers of the monosaccharide
glucose, alpha-glucose, D-glucose, or alpha-D-glucose
What type of bond forms between two sugar molecules?
glycosidic bond
The covalent bond formed between two monosaccharides by a dehydration reaction is called a(n) ____ 1linkage
glycosidic bond or linkage
Compared to unsaturated fats, saturated fats:
have a higher melting point pack together more tightly
The secondary structure shown in this diagram is an example of an alpha
helix
The two basic types of secondary structure are the alpha________ and the beta-pleated_____.
helix, pleated sheet
The reversible process by which a polymer is broken down into monomers is called
hydrolysis
Water is a reactant when a macromolecule is broken down in a ______ reaction, and water is a product when a macromolecule is formed in a ______ reaction.
hydrolysis; dehydration
amino acid side chains that are non-polar tend to minimize their contact with water; thereby excluding water and contributing to _________ effects involved in protein folding
hydrophobic
Lipids are
hydrophobic , nonpolar
Orgainic molecules are abundant
in living organisms
Dehydation reaction
in which monomers combine to form a polymer and a molecule of water is removed
Molecules that have identical molecular formulas but different structures are called
isomers
Enantiomers
isomers that are mirror images of each other
What type of organic molecule can assume both a linear or ring form?
monosaccharide
What type of monomers are combined to form carbohydrates?
monosaccharides
The main elemetns that make up proteins are ________,____ in addition to small amounts of other elements, like sulfur
nitrogen and oxygen
Carbon and hydrogen form
non polar bonds with carbon
hat are the two major structural components of phospholipids that make them amphipathic?
nonpolar fatty acids polar phosphate group
The nucleotides of DNA molecules contain the sugar, ________ as part of the backbone of the molecule.
pentose
What type of sugar are ribose and deoxyribose?
pentose
A type of covalent bond called a _______ bond forms between the carboxyl group of one amino acid and the amino group of another amino acid
peptide
In living things, starch is found in ______ cells and glycogen is found in certain types of ______cells.
plant , animal
In a phospholipid bilayer, the __________of the phospholipids face water and the___________regions face the interior of the membrane away from water.
polar and nonpolar
Phospholipids are amphipathic beacause they contain both
polar and nonpolar groups
Macromolecules are
polymers built from monomers. Large , complex organic Molecules
A protein is composed of one or more
polypeptides
When many monosaccharides are linked together, they form long carbohydrate polymers called
polysaccharides
amino acid sequence of a polypeptide is called the
primary structure
Hydrophobic effects play a major role in what protein structures?
quaternary structure and tertiary structure
dehydration
reaction, in which monomers combine to form a polymer and a molecule of water is removed.
Secondary
repetitive folding patterns such as helix and B pleated sheet
What are the two possible shapes formed by monosaccharides such as glucose?
ring and linear
Animals cells typically contain enzymes to break down the plant polysaccharide ______ to extract energy but not to break down the plant polysaccharide ______.
starch; cellulose
The backbone of a DNA or RNA strand is made of alternating________ and _______ molecules
sugar and phosphate
What is the primary structure of a protein
the amino acid sequence of a polypeptide
During proper base pairing in DNA, adenine pairs with_______ and cytosine pairs with _____ .
thymine , guanine
DNA and RNA are made of nitrogenous bases. Both DNA and RNA contain adenine, guanine, and cytosine. In addition, DNA contains the base _____, but RNA contains _______
thymine, Uracil
Which of the following is a correct name for fat molecules, one of the major classes of lipids?
triglycerides
True or false: A protein may be composed of more than one polypeptide.
true
How many. shells of electron does carbon have
two
Proteins that have quaternary structure consists of at least _______ polypeptides?
two or more
Quaternary
two or more interacting polypeptides
Which type of fatty acid contains one or more C=C double bonds?
unsaturated fatty acid
oils are fats that are high in
unsaturated fatty acids
an ______ fatty acid contains one or more c=c double bonds. An ______ fatty acid contains no C=C double bonds
unsaturated saturated
Which of the following nitrogenous bases are pyrimidines?
uracil , thymine, and cytosine
Lipids called______ help to prevent water loss from organisms
waxes
Hydrogen bonds can form _______
within a polypeptide and between different polypeptide chains
Amino group
(—NH2) a functional group composed of nitrogen atom bonded to two hydrogen atoms and to the carbon skeleton. Can act as a base in solution, accepting a hydrogen ion and acquiring a charge of +1.
sulfhydryl group
(—SH) a functional group consisting of a sulfur atom bonded to a hydrogen atom.
What are the three main properties of carbon that are important in forming organic molecules?
- carbon bonds are stable across a broad range of temperatures -Carbon can form multiple covalent bonds with other atoms -Carbon can form both polar and non polar bonds
hydrolysis reaction
A strand of DNA is broken down into individual nucleotides. A sugar is broken down into fructose and glucose molecules.
How can amino acid side chains affect the structure and function of a protein?
Amino acid side chains are involved in catalysis at the active site of enzymes. Amino acid side chains play a role in protein folding
How do the amino acid side chains affect proteins?
Amino acid side chains play a critical role in the structure and function of a protein.
Examples of dehydration reaction
Amino acids combine to form a long chain called a polypeptide. Several monosaccharides combine to form a polysaccharide.
What are the two types of secondary structure found in proteins
B pleated sheet a helix
Which of the following glycosidic linkages occur in cellulose ?
B-1,4 glycosidic linkages
Formula for glucose
C6H12O6
What are the four categories of macromolecules?
Carbohydrates, lipids, proteins, and nucleic acids
Which of the following accurately describes oils , such as olive oil?
Oils are fats high in unsaturated fatty acids. Oils have low melting points and are liquid at room temperature.
Molecules that contain carbon and that are found in all forms of life are called ______ molecules.
Organic
A monosaccharide with five carbon atoms is called a ________ sugar, and a monosaccharide with six carbon atoms is called an _____ sugar
Pentose, Hextose
What type of bond forms between two amino acids during a dehydration reaction?
Peptide bond
How are monomers and polymers related to one another?
Polymers are large macromolecules composed of many monomers linked together.
What level of protein structure occurs when two or more polypeptides interact with each other to form a functional protein ?
Quaternary
Disulfide bridges are covalent bonds between _______ groups of cysteine side chains.
SH
Fatty acids without carbon-carbon double bonds, such as the fatty acid shown here, are called _________ fatty acids.
Saturated
Typically, fats found in animals (usually solid) are _______ fats while fats found in plants (usually liquid) are ______fats.
Saturated, unsaturated
the_______ structure of a polypeptide is the repeating pattern of folding stabilized by hydrogen bonds
Secondary
which levels of protein structure are stabilized by hydrogen bonds?
Secondary structure , Quaternary structure and tertiary structure
Which of the following are examples of a dehydration reaction?
Several monosaccharides combine to form a polysaccharide. Amino acids combine to form a long chain called a polypeptide.
Where are the sugar phosphate groups and the nitrogenous bases found in the double helix?
The sugar phosphate backbone faces the outside of the double helix while the nitrogenous bases pair in the middle.
tertiary
The three-dimensional structure of a polypeptide
The two pyrimidine bases in DNA are
Thymine , Cytosine
Fats, a type of lipid, are also called _________and contain three fatty acids attached to glycerol.
Triglycerides
Disacccharides
Two monomers
A phospholipid moelcule consists of
a head that is polar and hydrophilic , and two tails that are nonpolar and hydrophobic
A phospholipid molecule consists of
a head that is polar and hydrophilic, and two tails that are nonpolar and hydrophobic.
Stereoisomers
a- and B- glucose hydroxly of carbon 1 is above or below ring D- and L- glucose
