Chapter 2 - Bonds

Question 1

How many naturally occurring elements are there?

Answer 1

92

Question 2

What is the most abundant substance in the cell?

Answer 2

Water

Question 3

What are the pyrimidines?

Answer 3

Thymine
Uracil
Cystine

Question 4

What are the purines?

Answer 4

Adenine

Guanine

Question 5

Which type of bond has pair of electrons that are shared between pairs of atoms?

Answer 5

Covalent bonds

Question 6

What is the major component of plant cell walls?

Answer 6

cellulose

Question 7

What term is used to describe the expanding field of protein biochemistry?

Answer 7

Proteomics

Question 8

Chemically what can cause water to be excluded from a region what is this called?

Answer 8

-lack of free tumble of water molecules (entropy)
-lack of hydrogen bond forming opportunities (enthalpy)
Hydrophobic effect

Question 9

When two specie associate due to charge neutralization what is this called?

Answer 9

Electrostatic interaction

Question 10

Two carbon atoms are very close together, and as such the nucleus of one atom is attracted to the electron cloud of the neighboring atom?

Answer 10

Van Der Waal

Question 11

What are the main elements of life? (5)

Answer 11

• hydrogen
• carbon
• oxygen
• nitrogen
• sulfur

Question 12

What is a polar bond?

Answer 12

A covalent bond where the electrons are shared unequally

Question 13

Why are weak bonds so important? (4)

Answer 13

• they can be formed/broken without huge changes in energy
• they are strong in large numbers
• they allow for small/temporary changes in structure
• they provide a degree of stability in structure

Question 14

What is the monomeric form of a protein?

Answer 14

Amino Acid

Question 15

What is the storage form of glucose in animal cells?

Answer 15

Glycogen

Question 16

What are the functions of sugars? (5)

Answer 16

• production/storage of energy
• cell walls
• Extracellular matrix
• DNA/RNA
• linked to proteins

Question 17

How are fatty acid monomers held together?

Answer 17

Hydrophobic effect

Question 18

What does amphipathic mean? Give an example of a molecule.

Answer 18

-a molecule that can associate w/hydrophilic and hydrophobic materials
I.E. Phospholipids

Question 19

What drives the formation of the secondary structure of a peptide chain?

Answer 19

Hydrogen bond formation between backbone atoms

Question 20

What is the single letter code for tryptophan?

Answer 20

W

Question 21

In a water molecule the bond between hydrogen and oxygen is best described as a?

Answer 21

Polar Covalent Bond

Question 22

When sodium and chlorine interact, the single electron in the outer shell of each sodium atom migrates to the electronegative chlorine atom. As a result these two atoms are transformed into charged _______.

Answer 22

Ions

Question 23

_________ are extremely reactive and capable of chemically altering many types of molecules, including proteins, Nucleic acids, and lipids.

Answer 23

Radicals

Question 24

What are considered a prion disease?

Answer 24

• BSE
• Kuru
• Creutzfeldt-Jakob Disease

Question 25

What are the reasons protein folding is a controversial topic?

Answer 25

- debates as to whether or not all of them are members of a population of unfolded proteins of a single species fold along a similar pathway or fold by means of a diverse set of routes that somehow converge upon some naive state. - debates among the types of events that occur at various stage during the following process - different interpretation of results that are required to study complex molecular events that occur on the microsecond timescale

Question 26

Which level of protein organization describes the conformation of portions of the polypeptide chain?

Answer 26

Secondary

Question 27

How many acids are incorporated into a protein encoded in the sequence of nucleotides in DNA?

Answer 27

20

Question 28

Some proteins fold into their final confirmation by themselves; others require assistance of nonspecific _________, which prevent aggregation of partial folded intermediates.

Answer 28

Chaperones

Question 29

A gram of fat contains ______ the energy content of a gram or carbohydrate.

Answer 29

6 times

Question 30

Water is an excellent solvent capable of forming hydrogen bonds w/virtually all_______ molecules.

Answer 30

Polar | Ionic

Question 31

What is an ionic bond?

Answer 31

A transfer of electrons (NaCl)

Question 32

What is a covalent bond?

Answer 32

Sharing of electrons (H2O)

Question 33

What are hydrogen bonds?

Answer 33

2 electronegative atoms attempting to share a positively charged ion between them

Question 34

What are electrostatic bonds?

Answer 34

Regions of positive charge interactions with a negative charge

Question 35

What is a Van Der Waals interaction?

Answer 35

Unshielded nucleus of an atom is attracted to the electron cloud of a nearby atom

Question 36

What are the properties of water? (3)

Answer 36

- highly asymmetric - highly polarized covalent bonds - oxygen is adept at forming hydrogen bonds

Question 37

What are the fates of the 4 major families of organic molecules?

Answer 37

Sugars become polysaccharides Fatty Acids become fats/lipids/membranes Amino acids become proteins Nucleotides become Nucleic acids

Question 38

What are the function of fats? (5)

Answer 38

- production and storage of energy - cell membranes - cell signaling - steroids - signal transduction

Question 39

What are the function of amino acids?

Answer 39

- generation of proteins | - energy source

Question 40

What is a peptide bond?

Answer 40

The bond that joins amino acids to a polypeptide chain. They result from the linkage of the carboxylic group of one amino acid group to the amino group of its neighbor w/the elimination of a molecule of water.

Question 41

What is a primary protein?

Answer 41

-protein described by the amino acid sequence of a polypeptide

Question 42

What is a secondary protein?

Answer 42

The 3D structures of the sections of the polypeptide backbone (alpha helix, beta sheet, random coil)

Question 43

What is a tertiary protein?

Answer 43

The conformation of the entire polypeptide (helices, sheets and coils that fold together)

Question 44

What is a quaternary protein?

Answer 44

Arrangement of subunits

Question 45

Why is the primary structure of protein tertiary?

Answer 45

- it is the most accessible structure w/lowest energy | - most thermodynamically stable

Question 46

What are the functions of nucleotides? (5)

Answer 46

- DNA (A,G,C,T) - RNA (A,G,C,U) - carries chemical energy (ATP) - signaling molecules - coenzymes

Question 47

The properties of cells and their organelles derive directly from the activities of the _______ of which they are composed.

Answer 47

Molecules