Biology Chapter 5: The Structure and Function of Large Biological Molecules
A polymer is
a long molecule consisting of many similar building blocks
The components of nucleic acids are __________.
a nitrogenous base, a pentose sugar, and a phosphate
Cholesterol is
a type of steroid
Fats are
constructed from two types of smaller molecules
The subunits (monomers) in cellulose are linked together by __________.
glycosidic linkages
Lipids are _________because they consist mostly of hydrocarbons.
hydrophobic
Lipids are a diverse group of _____________ molecules
hydrophobic
Which is the term for compounds that do not mix with water?
hydrophobic
Two fatty acid tails are __________, but the phosphate group and its attachments form a ____________ head.
hydrophobic, hydrophilic
Macromolecules are partners, built from _________.
monomers
Saturated fatty acids have
the maximum number of hydrogen atoms possible and no double bonds
What is the unifying feature of lipids?
they mix poorly if at all with water
Glycerol is a
three carbon alcohol with a hydroxyl group attached to each carbon
In a fat, there are ______ fatty acids that are joined to glycerol by an ester linkage, creating a _______________, or __________.
three, triacylglycerol, triglyceride
Fats separate from water because
water molecules hydrogen-bond to each other and exclude the fats
Bilayer arrangement
where the hydrophobic heads are on the outside while the hydrophobic tails are touching in the inside away from water Hydrophobic tails are pointing toward the interior
4 Classes of large biological molecules
Carbohydrates, Lipids, Proteins, and Nucleic acids
The 3 classes of life's organic molecules that are polymers are:
Carbohydrates, Proteins, and Nucleic acids
Which of the following is a polymer?
Cellulose, a plant cell wall component
A shortage of phosphorus in the soil would make it especially difficult for a plant to manufacture __________.
DNA
The sex hormones estrogen, progesterone, and testosterone belong to which class of molecules?
Lipids
Generally, animals cannot digest (hydrolyze) the glycosidic linkages between the glucose molecules in cellulose. How then do cows get enough nutrients from eating grass?
Microorganisms in their digestive tracts hydrolyze the cellulose to individual glucose units.
True or False: Certain unsaturated fatty acids are not synthesized in the human body
True
Sickle-cell anemia is a disease that is caused by __________ in the __________ of the protein.
a single amino acid change; primary structure
Human and other mammals store their long-term food reserves in ____________ cells.
adipose
Protein molecules are polymers (chains) of __________.
amino acid molecules
Large biological molecules have unique properties that arise from the orderly arrangement of their ________.
atoms
All living things are made up of four classes of large ____________________.
biological molecules
High levels of cholesterol in the blood may contribute to ____________ __________.
cardiovascular disease
The structure of phospholipids results in a bilayer arrangement found in _____________.
cell membranes
At a conference, the speaker's grand finale was sautéing mealworms (insect larvae) in butter and serving them to the audience. They were crunchy (like popcorn hulls) because their exoskeletons contain the polysaccharide __________.
chitin
The molecule with four fused rings that is found in animal membranes and is the precursor of vertebrate sex hormones is __________.
cholesterol
Trans fats
contribute more than saturated fats to cardiovascular disease
The type of bond that forms to join monomers (such as sugars and amino acids) into polymers (such as starch and proteins) is a(n) __________ bond.
covalent
Triacylglycerol is a
fat that consists of three fatty acids joined to glycerol by an ester linkage
The most biologically important lipids are :
fats, phospholipids, and steroids
Hydrocarbons
form nonpolar covalent bonds
The two types of smaller molecules that construct fats are
glycerol and fatty acids
A polysaccharide that is used for storing energy in human muscle and liver cells is __________.
glycogen
Steroids are
lipids characterized by a carbon skeleton consisting of four fused rings
The proper three-dimensional shape and folding of a protein is assisted by _________.
molecules called chaperonins
The repeating units that serve as building blocks for polymers are called
monomers
Fatty acids consist
of a carboxyl group attached to a long carbon skeleton
Essential fatty acids include:
omega-3 fatty acids
Unsaturated fatty acids have
one or more double bonds
The lipids that form the main structural component of cell membranes are __________.
phospholipids
A diet rich in saturated fats may contribute to cardiovascular disease though __________.
plaque deposits
Omega-3 fatty acids are
required for normal growth and are thought to provide protection against cardiovascular disease
The fatty acids in a fat can be all _________ or of ____ or ____ different kinds
same, two, three
Most animal fats are ___________.
saturated
Fats made from saturated fatty acids are called ____________ and are solid at room temperature
saturated fats
When phospholipids are added to water, they...
self-assemble into double-layered structures
Macromolecules, the molecules of life, include all of the following except __________. proteins nucleic acids carbohydrates trace elements
trace elements
Hydrogenating vegetable oils also creates unsaturated fats with _____ double bonds
trans
Plant fats and fish fats are usually ______
unsaturated
In a dehydration synthesis reaction, __________ is always formed as a by-product of the reaction.
water
The peptide bond is __________.
a covalent bond joining amino acids together to form a polypetide
Fatty acids vary in length and in the number and locations of ____________.
double bonds
The sequence of amino acids in a protein is called the __________ structure of the protein.
primary
Which type of protein shields a newly forming protein from cytoplasmic influences while it is folding into its functional form?
Chaperonins
In living organisms, DNA exists as a __________ with the strand(s) __________.
double helix; running antiparallel
One characteristic shared by sucrose, lactose, and maltose is that __________.
they are all disaccharides
When comparing saturated and naturally occurring unsaturated fats, the unsaturated fats have __________ and are __________ at room temperature.
cis double bonds; liquids
Bilayers are
doubled-layered structures
The major function of fats is__________.
energy storage
Lipids are
the one class of large biological molecules that does not include true polymers
Hydrogenation is
the process of converting unsaturated fats to saturated fats by adding hydrogen
In a phospholipids,
two fatty acids and a phosphate group are attached to a glycerol
Nitrogenous bases are classified as either purines or pyrimidines. Examples of purines are __________.
adenine and guanine
3 out of 4 classes of life's organic molecules are ______
polymers
Cholesterol is a component in animal cell membranes and a...
precursor from which other steroids are synthesized
Fats made from unsaturated fatty acids are called _____________ or ____ and are liquid at room temperature
unsaturated, oils
The secondary structure of a peptide backbone is stabilized by __________ forming either a(n) __________ or a(n) __________.
hydrogen bonds; α helix; β pleated sheet
The tertiary structure of a protein includes all of the following interactions except _________ bonds.
peptide
The existence of cells depends on______________.
phosphoipids
Adipose tissue also serves as:
a cushion for vital organs and insulates the body
Macromolecules are
large molecules and are complex
__________ is always involved in hydrolysis reactions.
Water
Carbohydrates are used in our bodies mainly for __________.
energy storage and release
Sugars are molecules that have __________ C:H:O and are called __________.
a 1:2:1 ratio of; carbohydrates
Sugars have a(n) __________ group that interacts with a _________ group that forms ring structures when the dry molecule is placed in water.
carbonyl (-C=O); hydroxyl (-OH)
