Name_______________________________
Reading Guide Chapter 3:
Proteins, carbohydrates and lipids
CHAPTER 3 GUIDED NOTES: THE CHEMICAL BUILDING BLOCKS OF LIFE
3.1
What are the 4 major groups of organic compounds (macromolecules) studied in biology?
___proteins, carbohydrates, lipids, nucleic acids_______
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1. Define the following:
a. monomer ___a single unit, also called a building block_______________________________
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b. polymer ___many monomers together____________________________________________
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2. What are the 4 major groups of organic compounds (macromolecules) studied in biology?
______ proteins, carbohydrates, lipids, nucleic acids ________________
3. What is the significance of functional groups?
______depending on the properties of the group , the molecule will
_______________________________________
4. Define the following types of reactions:
c. condensation reaction _a synthesis reaction that loses an H, OH (water molecule) to form a
larger molecule resulting in a covalent bond. Energy is added to the system
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d. hydrolysis __a reaction that separates a polymer by splitting a water molecule and using the O
and OH ions on the newly separated monomers._________
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3.2
5. List all eight types of functions of proteins and give a short description.
1.Enzymes- lowers activation energy of a reaction to speed up the reaction
2._Defensive proteins- Immune system molecules such as antibodies. __
3.Hormone regulatory proteins- insulin_____________________________________________
4.__receptor proteins that respond to signals ___
5.Storage proteins –stores chemical building blocks
6.___Structure- ex. collagen provides stability and movement ___
7.Transport- ex. Hemoglobin carries substances within organism ____
8.Genetic regulatory proteins- such as polymerase that regulates DNA, RNA
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6.What two functions are not performed by proteins? ____Energy storage and genetic information
storage___________________________
7.What are the five groups used to classify amino acids?
__amino acids that are charged, hydrophilic (-OH), Polar but uncharged, nonpolar hydrophobic (CH3), special cases.
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8. Sketch a protein molecule and label the amine, carboxyl and functional side chain.
Amine group
Carboxyl group
9. There are three special cases of amino acids. Name them and why they are important.
_______Cysteine- has sulfur that forms disulfide bridge during folding (tertiary structure)
________Glycine- has a hydrogen so it is small enough to fit into tight spaces _______
Proline- has amodified group with an amine group, lacks a hydrogen and so forms a ring structure.
Limiting its H bonding and its ability to rotate around the alpha carbon. found where the protein
bends or loops.
This would be a great time to watch the Lifewire web activity 3.2 Features of amino acids
7. What determines the primary structure of a protein?
______the sequence of the amino acids and the properties associated with the a.a. determine how
it folds, making each protein uniquely shaped.
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8. Describe the four levels of protein structure:
a. Primary __the poly peptide chain of amino acids_covalently bonded___________
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b. Secondary __the hydrogen bonding to form alpha helixes (rt handed coil) and beta sheets. (two
chains are aligned and form H bond between the N-H and C=O
c. Tertiary _the bending and folding of the molecule resulting in a 3D structure. uses Hyrogen
bonds, covalent disulfide bridges, ionic bonds.
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d. Quaternary ___polypeptide subunits bind together and form large functioning moleucles. the
weak bonds that hold the quaternary structure together allow for slight movement enhancing the
functioning of the protein. __________________________________________________________
9. Explain the role of chaperone proteins in protein folding.
_____When a protein has denatured (unfolded) it has a the possibility of refolding wrong or bonding
to another molecule. a chaperone is a structure that holds the protein , allows it to refold properly
then releases it .
10. What is the potential biological significance of improper folding of proteins.
the resulting protein will not function as it should resulting in no functioning or a different function.
_Ex. hemoglobin not folded properly doesn't maintain the correct shape, doesn't hold the oxygen
and both of these cause the person significant pain and stress.
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11. What happens to a protein during denaturation?
______________caused by high heat, change in pH, high conc. of polar substances, and non-polar
substances. these can disrupt the bonds of secondary and tertiary structures. Can be irreversible if
the inside hydrophobic groups are exposed to the surface.
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3.3
12. What are the three biological roles of carbohydrates?
______Source of stored energy, transport stored energy with in complex organisms, serve as
carbon skeletons that can be rearranged forming new molecules.
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13. List some monosaccharides with their molecular formulas.
__glucose- C6H12O6 _________________Pentoses- C5H10O5,C5H10O4 ex. deoxyribose and
ribose
____________ Hexoses- C6h12O6 isomers that have different sturctural shapes, ex.
galactose, fructose, mannose.
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14. Double sugars are called
____disaccharides_________________________________________________
15. List the monosaccharides that form each:
a. maltose _____glucose and glucose
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b. sucrose ______fructose and glucose
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c. lactose ___glucose and galactose__________________________________
16. Polymers of sugars form __polysaccharides
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What is a glycosidic linkage and why is it important? covalent_bond that hold the monosaccharide
together. can create many different disaccharides depending on the monosaccharide they link.
_______________________________
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17. Which forms of polysaccharide is best for each function:
a. Strength of structure _____cellulose, due to the beta linkages, more stable not easily broken
down in harsh environment conditions. ____________________
b. Storage and sugar release __Starch and glycogen. Starch is principle storage in plants. glycogen
is principle storage in animals specifically liver and muscle.
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18. How does the alpha differ from the beta form of glucose and why is it significant to animals?
________________in Beta- the OH alternates up and down so the bonds form parallel fibers that
are strong (cellulose) and not easily broken down by animals. the starch and glycogen are formed
by alpha linkages that produce branching. this polysaccharide can be easily broken down for
Energy in animals. _____________________________________________________________
19. How do the role and structure of the following polysaccharides compare?
a. starch ____branching polysaccharide that forms in plants (potatoes, fruit).
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b. glycogen _____animal storage of sugars.
c. cellulose ___main component of cell walls, not easlily broken down.
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d. chitin ___________a chemically modified carb that has an amino group. glucosamine makes up
chitin a structural polysaccharide in external skeletons of insects and crustaceans. and cell walls of
fungi. (most abundant substances in living world)
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3.4
20. What is the characteristic common to lipids?
_______insoluble in water due to many nonpolar covalent bonds.
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21. How do phospholipids interact in an aqueous solution?
____hydrophobic tails move away from water. ____________________________
22. Make a diagram of phospholipid interactions that form membranes.
Use p 56, be able to recognize the phospholipid bilayer
23. What makes fats hydrophobic?
_____it is the C-C and C-H bond in the fatty acid tails. the carboxyl functional group at the end of
the molecule is hydrophiic. making the molecule amphipathic.
______________________________________
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24. State at least two differences between saturated and unsaturated fats.
a. ______Saturated have all the bonds of H that it can hold. all single bonds. very rigid and
straight_____________________________
b. __contains one or more double bond. causes a kink in the molecule prevents it from packing
tightly. _______________________________
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215. Name four types of steroids and state the common structure they all have in common.
______cholesterol- important i membranes _______Vitamin- important for the diet. _____cortisoltype of hormone secreted by glands and testosterone- male sex hormone. All have same ring
structure. and are highly hydrophobic.
26. What is the main function of fats? ____Long term energy storage, strucuteal- cell membrane,
carentenoids that are light absorbing pigments in plants, steriods and vitamins both essential to the
body, and waxes found in leaves and animals.
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