Bio 160 Test 1

Front 1

Valence

Back 1

the unpaired electrons

Front 2

Valence Shell

Back 2

the outermost electron orbital

Front 3

Valence electrons

Back 3

all the electrons in the valence shell

Front 4

Electric charge, Mass (Da) of electron

Back 4

-1,0

Front 5

Electric charge, Mass (Da) of proton

Back 5

+1,1

Front 6

Electric charge, Mass (Da) of neutron

Back 6

0,1

Front 7

Covalent Bonds

Back 7

electrons are shared between two atoms

Front 8

NONPOLAR

Back 8

NO CHARGE all electrons are shared equally (example: H2) electronegativity difference is 0-0.5

Front 9

POLAR

Back 9

PARTIAL CHARGE the electronegative atoms holds onto e- tightly. The electronegative atom has partial – charge, other atoms have partial + charge (example: H2O) electronegativity difference is 0.5-1.7

Front 10

Electronegativity from most to least

Back 10

O > N > C =S ~ H

Front 11

Ionic Bonds

Back 11

FULL CHARGE. electrons are transferred from one atom to another (one loses e-, the other gains e-, so one has – charge and one has a + charge.) (example: Na+ Cl- --> NaCl) electronegativity difference is >1.7

Front 12

HYDROPHILIC

Back 12

“Water-loving”. Polar molecules (Electrons are pulled toward oxygen) and ions are SOLUBLE in H2O. Electrostatic attractionThings with charges (+ or -). Atom carrying + charge will interact with Oxygen (which has partial – charge), atoms carrying – charge will interact with Hydrogen (which has partial + charge). ****REMEMBER: “Like Dissolves Like” ****

Front 13

HYDROPHOBIC

Back 13

“Water-fearing”. Nonpolar molecules are INSOLUBLE in H2O. No charge with which to interact with water.

Front 14

Hydrogen Bonds

Back 14

Weak electrical attraction·

No electron sharing·

Between H that has a partial + charge and an atom with partial – charge·

Other molecules besides water can form hydrogen bonds

Front 15

Which type of bond must be broken for water to vaporize?

Back 15

Hydrogen bonds

Front 16

Acidic solutions

Back 16

Higher concentration of H+ ~0-5 pH. any compound that gives up protons or accepts electrons during a chemical reaction or that releases hydrogen ions when dissolved in water.

Front 17

Neutral solutions

Back 17

pH of 7 is completely neutral ~6-8 pH

Front 18

Basic solutions

Back 18

Higher concentration of OH- ~9-14 pH. any compound that acquires protons or gives up electrons during a chemical reaction or accepts hydrogen ions when dissolved in water.

Front 19

Hydrophobic R Chains

Back 19

(NONPOLAR). Only C, H, S will be present in side chain (with exception of one side chain that contains N; Tryptophan)

Front 20

Polar R Chains

Back 20

(Hydrophillic). If it contains Oxygen with PARTIAL CHARGES (you’ll know it is not Ionic if no FULL charges are shown. So O without a charge shown = polar side chain)

Front 21

Ionic R Chains

Back 21

(also Hydrophillic). If there is a full charge (- or +) in the side chain, either on the O or N, it is ELECTRICALLY CHARGED and IONIC. (If O has a – next to it, it’s Ionic. If it’s got Oxygen in it with no charges next to it, it’s Polar).

Front 22

Primary Protein Structure

Back 22

unique sequence of amino acids Peptide Bonding holds primary structure together (peptide bonds are covalent bonds)

Front 23

Secondary Protein Structure

Back 23

three- dimensional form of short amino acid sequences created by hydrogen bonding. Depends on the primary structure. Hydrogen bonding that occurs between the C=O group of one amino acid and the Hydrogen on the N-H group of another amino acid. Although Hydrogen bonds are usually weak compared to covalent bonds, the quantity of hydrogen bonds makes these structures highly stable. Alpha helices or beta helices

Front 24

α-Helices

Back 24

the polypeptide’s backbone is coiled (this is the most common secondary structure of proteins). In this form, H-bonds form between residues that are only 4 linear positions apart in the primary sequence.

Front 25

β-Pleated Sheets

Back 25

segments of a peptide chain bend 180° and then fold in the same plane.

Front 26

Tertiary Protein Structure

Back 26

three-dimensional form of polypeptide. Are diverse, defines the function

Front 27

5 types of interactions involving side chains are important:

Back 27

1. Hydrogen Bonding

2. Hydrophobic interactions

3. Van der Waals interactions

4. Covalent Bonding (S-S disulfide bonds!)

5. Ionic Bonding

Front 28

Quaternary Protein Structure

Back 28

directed by primary protein structure defines its function. Proteins are the most versatile large molecules in the cell. Not all proteins have this· Many proteins contain several distinct polypeptide subunits that interact. Combinations of many tertiary structures that bond together

Front 29

general idea of how protein folding occurs and what factors influence it.

Back 29

Protein folding is often spontaneous; the folded molecule is more energetically stable than the unfolded molecule. Because of the hydrogen bonds and van der waals interactions That make the folded molecule more energetically stable than the unfolded molecule. Protein folding is often regulated. Regulates protein activity Since the function of a protein is dependent on its shape, it controls when or where it is folded which regulates the activity. A denatured (unfolded) protein is unable to function normally. Denature a protein with heat or in other ways. When you unfold it, it completely kills the function. Protein folding is also often regulated: regulation depends on the primary structure (the sequence of amino acids) and the environmental conditions

Front 30

Describe the structure of a nucleotide

Back 30

Phosphate Group, 5-carbon sugar (Ribose in RNA, Deoxyribose in DNA), Nitrogenous Base (A, T, C, G, with the T substituting for U in RNA).

Front 31

explain how nucleotides polymerize to form nucleic acids

Back 31

Polymerize via Condensation Reaction

Front 32

Explain importance of hydrogen bonds for structure of DNA and RNA

Back 32

Hydrogen bonds form between the complementary base pairs on antiparallel strands. Adenine has a double hydrogen bond with Thymine (or Uracil in RNA), Guanine has a triple hydrogen bond with Cytosine. The hydrogen bonding between base pairs stabilizes the DNA molecule

Front 33

Compare and contrast RNA and DNA in their structure and function

Back 33

-DNA has adenine, guanine, cytosine and thymine

-RNA has adenine, uracil, cytosine and guanine

-In RNA, Adenine and Uracil pair

-In DNA, Adenine and Thymine pairIn RNA

-there is an OH on the 2’ carbon of the riboseIn DNA

-there is an H on the 2’ carbon of the deoxyribose

Front 34

Describe similarities and differences in primary structure

Back 34

RNA has an oxygen on its riboses carbon 2 while DNA lacks this and only has a hydrogen, RNA has uracil rather than thymine, they both have a diester phosphate back bone that is formed through a condensation reaction

Front 35

Describe similarities and differences in secondary structure

Back 35

DNA is normally in the double helix form and RNA can be flat and is often bound to itself in a structure with a loop at one end

Front 36

Describe differences in function and stability

Back 36

RNA can function to regulate gene expression or carry gene information outside of the cell nucleus as well as other things, DNA primarily serves as a template for cell duplication protein syntheses and is more stable due to the lack of oxygen on its carbon 2 and the hydrogen bonds that stabilize it

Front 37

Explain the role of complementary base pairing in the replication of DNA

Back 37

Allows for easy replication of DNA. There is only one base that can pair with another, so it eliminates ambiguity and allows for two daughter DNA to be identical

Front 38

Explain how DNA is arranged in cell and how does this differ in prokaryotes and eukaryotes

Back 38

eukaryotes have nucleus and chromosomes and prokaryotes don’t, also prokaryotes dna is often a single loop inside the cell. Eukaryotic DNA is linear while Prokaryotic DNA is circular

Front 39

Explain evolutionary origin of nuclear envelope

Back 39

The plasma membrane folded in on itself, surrounding the chromosomes in the center, until eventually it became the nuclear envelope that protects the genetic material within.