Principles of Biology- Macromolecules: carbohydrates and lipids
What are the functions of fats in living organisms?
1) Energy Storage 2) Support cushion for organs 3) Insulation
How do fatty acids found in fats and other lipids differ from one another?
1) Fatty acids differ in length of the hydrocarbon chain. 2) Fatty acids differ in the presence or amount of double bonds.
Which monosaccharides are commonly found in nature?
1) Galactose 2) Glucose 3) Fructose
What three polysaccharides play a structural role in organisms?
1) Glycosaminoglycans 2) Chitin 3) Cellulose
What are the parts that make up the polar hydrophilic region of a phospholipid molecule.
1) Phosphate group 2) Charged Nitrogen-containing region 3) Glycerol backbone
Which polysaccharides are used for energy storage in cells?
1) Starch 2) Glycogen
Why do phospholipids arrange into bilayers?
1) The bilayer is the most energetically favorable arrangement in aqueous solution. 2) The hydrophilic ends attract water while the hydrophobic ends exclude water.
What is a fatty acid?
A chain of carbon and hydrogen atoms with a carboxyl group at one end.
During the synthesis of a triglyceride, what is attached to glycerol in each dehydration reaction?
A fatty acid
A phospholipid molecule consists of
A head that is polar and hydrophilic, and two tails that are nonpolar and hydrophobic.
The most common hexose is
Glucose
A phospholipid consits of a
Glycerol attached to two fatty acids and a phosphate group
Fats, or triglycerides, are composed of:
Glycerol covalently bound to three fatty acids
What type of bond forms between two sugar molecules?
Glycosidic Bond
Polysaccharide
Many Monomers
What are the sources of variation in lipid molecules?
The length of the fatty acids and presence of double bonds
Which regions of a phospholipid bilayer face water and which face the interior of the membrane away from water?
The polar regions face water, and the nonpolar regions face the interior
Pentose sugars have ________ carbon atoms, and hexose sugars have ________ carbon atoms.
a) 5 b)6
The amount of energy a fat contains is determined by how many bonds it has between __________ atoms and _________ atoms.
a) Hydrogen b) Carbon
In a phospholipid bilayer, the ___________ regions of the phospholipids face water and the ____________ regions face the interior of the membrane away from water.
a) Hydrophilic b) Hydrophobic
A monosaccharide with five carbon atoms is called a ___________ sugar, and a monosaccharide with six carbon atoms is called a _________ sugar.
a) Pentoses b) Hexoses
Fats consist of three fatty _______ covalently bonded to a three-carbon molecule called _________
a) acids b) glycerol
Fats consist of three fatty ________ covalently bonded to a three-carbon molecule called _______
a) acids b) glycerol
A chain of carbon and hydrogen atoms with a carboxyl group at one end is called a:
fatty acid
Carbohydrate polymers are called
polysaccharides
Three chemical elements that are found in all carbohydrates are ...
Carbon, Hydrogen, and Oxygen
How are fats synthesized?
Dehydration synthesis links three fatty acids to glycerol.
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.
Cells extract _________ from glucose by breaking its bonds.
Energy
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 allows 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
Starch, glycogen, and cellulose are all polymers of the monosaccharide
Glucose
The covalent bond formed between two monosaccharides by a dehydration reaction is called a(n) __________ linkage
Glycosidic
Glycogen
Highly Branched
Lipids are molecules that are composed of primarily what two elements?
Hydrogen and Carbon
What type of chemical reaction can break down a polysaccharide into monosaccharides?
Hydrolysis
The C=C double bonds in fatty acids introduce a(n) _________ into the linear shape of the fatty acid chain.
Kink
Starch
Moderate Branching
What type of organic molecule can assume both a linear or ring form?
Monosaccharide
Polysaccharides can be hydrolyzed in the presence of water. what is the product of this reaction?
Monosaccharides
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
In an aqueous environment, phospholipids form lipid _________ with hydrophobic ends facing the interior because this is energetically most favorable for these molecules.
bilayer
Carbohydrate monomers are known as
monosaccharides
Glucose and galactose are examples of:
monosaccharides
A long hydrocarbon chain resembling a fatty acid attached by its carboxyl group to another long hydrocarbon chain is best described as a(n)
wax
How do cells obtain energy from glucose?
By breaking its bonds and using the energy they store to build ATP
What is the chemical formula of glucose?
C6H12O6
A fatty acid that is polyunsaturated contains two or more
C=C bonds.
Monosaccharide
One monomer
What type of sugar are ribose and deoxyribose?
Pentose
What type of lipid consists of a molecule of glycerol attached to one phosphate group and two fatty acids?
Phospholipid
When many monosaccharides are linked together, they form long polymers called
Polysaccharides
Fatty acids without carbon-carbon bonds are called
Saturated fatty acids
In what organisms are starch and glycogen found?
Starch is found in plants and glycogen is found in animals.
Disaccharide
Two Monomers
Cellulose
Unbranched
Which type of fatty acid contains one or more C=C double bonds?
Unsaturated fatty acids
What type of lipid consists of ling structures resembling fatty acids attached to each other by their carboxyl groups?
Wax
