Study Guide: Chapter 3

Question 1

Why is carbon so important in biochemistry?

Answer 1

• almost all the molecules a cell makes are composed of carbon atoms bonded to one another
• it is unparalleled in its ability to form large and complex molecules that build the structures and carry out the functions of life

Question 2

Isomers

Answer 2

compounds with the same formula but different structural arrangements

Question 3

Macromolecules

Answer 3

carbohydrates, lipids, proteins, nucleic acids. often called polymers.
a giant molecules (a polysaccharide, protein, nucleic acid) formed by the joining of smaller molecules usually by dehydration reaction

Question 4

polymers

Answer 4

• a large molecule consisting of many identical or similar monomers linked together by covalent bonds
• a long molecule consisting of many identical or similar building blocks strung together, much as a train consists of chain cars. The building blocks of polymers are called monomers.

Question 5

Dehydration synthesis

Answer 5

• a reaction that removes a molecule of water as two molecules become bonded together. each monomer contributes part of the water molecule that is released during the reaction
• a chemical reaction in which two molecules become covalently bonded to each other with the removal of a water molecule

Question 6

Hydrolysis

Answer 6

a chemical reaction that breaks bonds between two molecules by the addition of water; process by which polymers are broken down and an essential part of digestion. Essentially the reverse of dehydrations synthesis

Question 7

Carbohydrates

Answer 7

class of molecules that range from small sugar molecules such as those dissolved in soft drinks to large polysaccharides such as the starch molecules we consume in pasta and potatoes

Question 8

monosaccharide

Answer 8

• aka simple sugars
• they are the monomers of carbohydrates.
• the simplest carbohydrate, a simple sugar with a molecular formula that is generally some multiple of CH2O. they are monomers or disaccharides and polysaccharides

Question 9

Disaccharide

Answer 9

a sugar molecule consisting of two monosaccharides linked by a dehydration reaction
(maltose, malt sugar)

Question 10

Polysaccharide

Answer 10

• a carbohydrate polymer of many monosaccharides (sugars) linked by dehydration reaction
• macromolecules

Question 11

Glucose

Answer 11

• C6H12O6; isomer of fructose
• Biological function: cellular respiration, major source of energy for cells (atp)
• immediate energy source to tissues in need of repair

Question 12

Fructose

Answer 12

• C6H12O6; isomer of glucose

- Biological function: source of energy for cells (like glucose)

Question 13

Sucrose

Answer 13

most common disaccharide. made of a glucose monomer linked to a fructose monomer. Provides a source of energy and raw materials to all parts of the plane

Question 14

Maltose

Answer 14

formed from two glucose monomers. can be used for energy, store energy

Question 15

starch

Answer 15

a storage of polysaccharide in plants, consists of long chains of glucose monomers. Plants use it to store energy long term

Question 16

glycogen

Answer 16

an extensively branched storage polysaccharide found in liver and muscle cells, the animal equivalent of starch
can be used for energy, store energy

Question 17

cellulose

Answer 17

a structural polysaccharide of plant cell walls composed of glucose monomers. cellulose molecules are linked by hydrogen bonds into cable like-like fibers
main structure of plans, undigestable? fiber

Question 18

chitin

Answer 18

a structural polysaccharide found in many fungal cell walls and in the exoskeletons of arthropods
polymer of modified glucose
-insect shells
-fungi

Question 19

Lipid

Answer 19

diverse group of molecules that are classified together because they do not mix well with water.
an organic compound consisting mainly of carbon and hydrogen atoms linked by nonpolar covalent bonds, making the compound mostly hydrophobic. lipids include fats, phospholipids, and steroids and are insoluble in water

Question 20

protein

Answer 20

polymer of specific amino acids
1 named protein has 1 job
protein job is determined by its shape which is caused by a specific amino acid sequence which is found in the gene

Question 21

steriod

Answer 21

type of lipid cell whose carbon skeleton is in the form of four fused rings with various chemical groups attached
cholesterol-helps cell membranes work
hormones- testosterone, estrogen