Chapter 3: Molecules of Biology

Question 1

organic

Answer 1

• molecules and compounds that contain carbon

- proteins, carbohydrates, lipids, nucleic acids

Question 2

inorganic

Answer 2

• molecules that do not contain carbon

- exception: CO2

Question 3

amino acids

Answer 3

• 20 different monomers of proteins (the polymer)

- memorize structure of the backbone of amino acid

Question 4

peptide bond

Answer 4

• bond between polypeptide chains that is formed through dehydration synthesis (the removal of H2O)
• OH of carboxyl group and H of amino group combine together
• broken through hydrolysis (addition of H2O)

Question 5

protein function

Answer 5

• enzyme
• hormone
• channels
• structural elements
• carriers
• messengers

Question 6

carbohydrate

Answer 6

• unique: monosaccharide/a single saccharide (monomer) can be called a carbohydrate
• made only of CHO… C:H:O ratio–> 1:2:1
• sugar molecules

Question 7

glucose and fructose

Answer 7

• monosaccharide with formula C6H12O6
• differ in way double bonded oxygen is oientated
• glucose can form a ring structure

Question 8

maltose

Answer 8

-disaccharide formed from 2 glucose molecules through removal of one water
C12H22O11

Question 9

sucrose

Answer 9

-disaccharide that is formed when one glucose combines with one fructose in dehydration synthesis
C12H22O11

Question 10

polysacchardies

Answer 10

• more than two monosaccharides combined together
• glycogen: animals store glucose
• starch: plants store glucose
• cellulose: forms the plant’s cell walls
• differ in way glucose molecules are linked together

Question 11

lipid function

Answer 11

• energy storage compounds
• components of cell membranes
• provide insulation and cushioning

Question 12

hydrocarbon

Answer 12

• monomer of lipids are fatty acids and glycerol
• carbon atom with two hydrogen atoms bonded to it
• hydrocarbon chains are typically 12-24 carbons long and are hydrophobic (nonpolar)

Question 13

types of lipids

Answer 13

• triglycerides
• cholestrol
• phospholipids

Question 14

triglycerides

Answer 14

• 3 fatty acids (hydrocarbon chain with carboxyl group at the end) bonded to a glycerol (alcohol with three carbon atoms)
• fat is stored in this form

Question 15

phospholipids

Answer 15

• 2 fatty acids, one phosphate group, 1 glycerol
• polar (hydrophilic) on phosphate side (head), nonpolar on fatty acid end (tail)
• form lipid bilayer

Question 16

cholestrol

Answer 16

• hydrocarbons form rings
• found only in animal cells in the cell membrane to maintain and build cell membrane
• steroid hormones (hydrophobic) are derived from cholestrol
• also found in blood and body tissues
• good cholestrol: HDL
• bad cholestrol: LDL

Question 17

nucleic acids

Answer 17

• typically found in nucleus of the cell
• monomer: nucleotide
• polymer: nucleic acid (polynucelotide), ex. are DNA and RNA
• nucelotide: backbone (phosphate, sugar), base
• nucleic acids are the different strands of DNA
• order of the nucleotide changes the strand of DNA
• C and G form triple hydrogen bond (more stable)
• A and T form double hydrogen bond
• A and G are purines (larger molecule)
• C and T are pyridimines

Question 18

RNA

Answer 18

• single-strandedness allows for it to assume many different shapes (not restricted by the double helix)
• can form base pairs with itself
• uracil instead of thymine

Question 19

atoms

Answer 19

-fundamental units of the physical world

Question 20

molecule

Answer 20

-composed of individual atoms combined together

Question 21

element

Answer 21

-molecule with only one type of an atom

Question 22

compound

Answer 22

-molecule with different types of atoms combined in an ionic bond

Question 23

macromolecule

Answer 23

-large organic molecule

Question 24

polymer

Answer 24

-strings of repeated units

Question 25

monomers

Answer 25

-individual units of a polymer

Question 26

protein

Answer 26

• many amino acids in a long chain
• also known as a polypeptide (held together by peptide bonds)
• have 3D shapes and different functions

Question 27

lipid

Answer 27

-fats

Question 28

DNA

Answer 28

• double spiral of DNA strands (double helix) that was discovered by Watson and Crick (using the work of Rosalind Franklin and Maurice Wilkins)
• two strand of DNA line up next to each other so that the bases bond together and form the rungs and the sugar-phosphate forms the sides of the ladder

Question 29

complementary DNA strands

Answer 29

-two strands of DNA that can form base pairs with each other at the nucleotide