The Structure and Function of Large Biological Molecules

Question 1

What is a dehydration reaction?

Answer 1

Two monomers bond together through a loss of a water molecule

Question 2

How are polymers disassembled to monomers?

Answer 2

By hydrolysis

Question 3

What is hydrolysis?

Answer 3

A reaction that is essentially the reverse of the dehydration reaction

Question 4

What are carbohydrates?

Answer 4

Sugars and polymers of sugars (Ex. monosaccharides or simple sugars)

Question 5

What are monosaccharides?

Answer 5

Molecular formulas that are usually multiples of CH20

Question 6

What is a disacharide?

Answer 6

When a dehydration reaction joins two monosaccharides

Question 7

What is the covalent bond between two monosaccharides called?

Answer 7

A glycosidic linkage

Question 8

What are plastids?

Answer 8

Storage structures

Question 9

What is glycogen?

Answer 9

A storage polysaccharide in animals, stored mainly in liver and muscle cells

Question 10

What is a major component of the tough wall of plant cells?

Answer 10

The polysaccharide “cellulose”

Question 11

What are lipids?

Answer 11

The one class of large biological molecules that do not include true polymers

Question 12

What is the unifying feature of lipids?

Answer 12

They mix poorly, if at all, with water

Question 13

What do lipids consist mostly of?

Answer 13

Hydrocarbon regions

Question 14

What are the most biologically important lipids?

Answer 14

Fats, phospholipids, and steroids

Question 15

What are fats constructed from?

Answer 15

Glycerol and fatty acids

Question 16

What is the major function of fats?

Answer 16

Energy storage

Question 17

What are the characteristics of saturated fatty acids?

Answer 17

Maximum number of hydrogen atoms and no double bonds

Question 18

What are the characteristics of unsaturated fatty acids?

Answer 18

One or more double bonds

Question 19

What is a phospholipid?

Answer 19

When two fatty acids and a phosphate group are attached to glycerol

Question 20

Are phospholipids hydrophobic or hydrophilic?

Answer 20

The two fatty acid tails are hydrophobic but the phosphate group and its attachments form a hydrophilic head

Question 21

What are steroids?

Answer 21

Lipids characterized by a carbon skeleton consisting of four fused rings

Question 22

What is cholesterol?

Answer 22

A type of steroid and a component in animal cell membranes and a precursor from which other steroids are synthesized

Question 23

What do protein functions include?

Answer 23

Defense, storage, transport, cellular communication, movement, and structural support

Question 24

What are polypeptides?

Answer 24

Unbranched polymers built from amino acids

Question 25

What is the bond between amino acids called?

Answer 25

A peptide bond

Question 26

What is a protein?

Answer 26

A biologically functional molecule that consists of one or more polypeptides

Question 27

What are amino acids?

Answer 27

Organic molecules with amino and carboxyl groups

Question 28

What are the four levels of protein structure?

Answer 28

The primary structure: its unique sequence of amino acids The secondary structure: found in most proteins, consists of coils and folds in the polypeptide chain Tertiary structure: determined by interactions among various side chains (R groups) Quaternary structure: results when a protein consists of multiple polypeptide chains

Question 29

Typical secondary structures are a coil and a folded structure called what?

Answer 29

α helix ; β pleated sheet

Question 30

What are the interactions that contribute to the Tertiary structure?

Answer 30

Hydrogen bonds, ionic bonds, hydrophobic interactions, and van der Waals interactions

Question 31

What may reinforce the protein's structure?

Answer 31

Strong covalent bonds called disulfide bridges

Question 32

What is collagen?

Answer 32

A fibrous protein consisting of three polypeptides coiled like a rope

Question 33

What is hemoglobin?

Answer 33

A globular protein consisting of four polypeptides: two α and two β subunits

Question 35

What affects protein structure?

Answer 35

Physical and chemical conditions

Question 36

What can cause a protein to unravel?

Answer 36

Alterations in pH, salt concentration, temperature, or other environmental factors

Question 37

What is the loss of a protein's native structure called?

Answer 37

Denaturation

Question 38

What are the two types of nucleic acids?

Answer 38

Deoxyribonucleic acid (DNA) and Ribonucleic acid (RNA)

Question 39

DNA provides what?

Answer 39

Directions for its own replication

Question 40

What is gene expression?

Answer 40

When DNA directs synthesis of mRNA and controls protein synthesis

Question 41

The flow of genetic information can be summarized as what?

Answer 41

DNA -- RNA -- protein

Question 42

How are nucleotides linked together?

Answer 42

By a phosphodiester linkage to build a polynucleotide

Question 43

What does a phosphodiester linkage consist of?

Answer 43

A phosphate group that links the sugars of two nucleotides

Question 44

What does a phosphodiester linkage create?

Answer 44

The backbone of sugar-phosphate units with nitrogenous bases as appendages

Question 45

Is the sequence of bases along a DNA or mRNA polymer unique for each gene?

Answer 45

Yes

Question 46

What does adenine pair with?

Answer 46

thymine and uracil

Question 47

what does guanine pair with?

Answer 47

cytosine

Question 48

What is it called when only certain bases in DNA are able to pair up and form hydrogen bonds?

Answer 48

Complementary base pairing

Question 49

What does complementary base pairing make possible?

Answer 49

For DNA structure to generate two identical copies of each DNA molecule in a cell preparing to divide

Question 50

How does RNA differ from DNA?

Answer 50

DNA forms double strands; RNA is typically single stranded DNA uses deoxyribose; RNA uses ribose DNA uses thymine; RNA uses uracil