Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Microbio > Lecture 2 > Flashcards

Lecture 2 Flashcards

1
Q

Types of Chemical Bonds

A
  • van der Waals interactions – dipole moment dependent, very weak
  • Hydrogen bond – polar molecules, due to electronegative atom being bound to nonelectronegative atom, very weak
  • Ionic bond – electrostatic interaction between oppositely charged molecules or functional
    groups, relatively weak
  • Hydrophobic interactions – non-polar molecules or regions of molecules interact to prevent
    association with aqueous environments
  • Covalent bond – formed by sharing of electrons to complete valence shell, very strong;
    single, double, or triple
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

The Versatility of the Carbon Atom

A
  • Carbon-carbon covalent bonds essential for life
  • Carbon atoms can form 4 chemical bonds
  • Provides versatility essential for life
  • Can link to a carbon or other type of atom
  • Carbon bonds - excellent for backbones of large molecules
  • Strong enough to hold molecule together
  • Not too strong to prevent cell from breaking
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Making Carbon Atoms “Spicy” Addition
of Functional Groups

A
  • Carbon-carbon bonds - non-polar
  • Makes them chemically and biologically “boring”
  • Hydrophobic
  • Chemically non-reactive
  • Addition of functional groups makes them more
    reactive
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Hydroxyl group

A

Hydroxyl group (alcohol) - addition of -OH to carbon,
very polar, affects solubility and reactivity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Carbonyl group

A

Oxygen double bonded to carbon
Two types, adehyde and keytone, both are polar

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Aldehyde carbonyl group

A

carbon double bonded to
oxygen and bonded to at least 1 hydrogen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Keytone carbonyl group

A
  • carbon double bonded to
    oxygen and two other carbon atoms
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Carboxyl group

A

carbon double
bonded to oxygen and single bonded
a hydroxyl group, very polar and
weakly acidic, due to high
electronegativity of oxygen atom;
proteins, fatty acids.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Amino group

A

carbon bonded to
nitrogen that is bound to 2 hydrogens,
polar, weakly basic, due to high
electronegativity of nitrogen atom;
proteins, nucleotides.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Methyl group

A

carbon bonded to at least 3
hydrogens, non-polar, extremely
hydrophobic; fatty acids, proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Phosphate ester group -

A

phosphorus single
bonded to 2 hydroxyls, double bonded to
one oxygen, and single bonded to a second
oxygen. Single bonded oxygen attaches
group to carbon chain, very polar, weakly
acidic; nucleotides and lipids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Sulfhydryl group

A

carbon bound to a sulfur
atom that is bound to a hydrogen atom.
Important in protein structure.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Ester

A

carbon bound to a carboxylic acid group,
lipids, attachment of amino acids to nucleotides

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Thioester

A

carboxylic acid group attached to a
sulfur; energy metabolism – biosynthesis of fatty acids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Ether

A

oxygen joining two carbons, sphingolipids
and lipids of Archea

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Acid Anhydride

A

carboxylic acid bound to
phosphate; energy metabolism

17
Q

Phosphoanhydride

A

two phosphates joined
together; high energy bond of ATP

18
Q

Assembly of Biological Macromolecules

A
  • Majority of biological molecules carbon based – organic
  • Pure carbon/hydrogen molecules hydrophobic
  • Hydrophobicity limits usefulness in aqueous environments
  • All biological processes require water
  • Addition of functional groups increases solubility in water
  • Dramatically increases versatility of carbon based molecules in biological systems
  • Carbon based molecules comprise four major classes of biologically relevant macromolecules
19
Q

Many Different Types of Polymers in Biological Systems

A
  • Carbohydrates
  • Lipids
  • Proteins
  • Nucleic Acids
20
Q

Carbohydrates

A
  • Monosaccharide - simple sugar, usually
    3 to 7 carbon atoms
  • 5 and 6 carbon sugars can be
    circular molecules
  • Hydroxyl group bound to each
    carbon except 1
  • One carbon is bound to a carbonyl
    group
  • 5 carbon sugars – important
    structural role in nucleic acids
  • 6 Carbon sugars commonly used as
    energy source
21
Q

Complex Carbohydrates

A
  • Long chains of carbohydrates – covalently attached by
    glycosidic bond
  • Three types of glycosidic bonds
  • a-1,4 – 1carbon from one sugar covalently attached to 4
    carbon of adjacent sugar, hydroxyl group on anomeric carbon
    beneath the plane of the ring
  • a-1,6 – 1 carbon from one sugar attached to 6 carbon on
    adjacent sugar, hydroxyl group on anomeric carbon beneath the
    plane of the ring
  • b-1,4 – 1 carbon from one sugar attached to 4 carbon of
    adjacent sugar, hydroxyl group on anomeric carbon above the
    plane of the ring
22
Q

Starch and glycogen

A
  • Starch and glycogen – energy storage for plants and
    animals, respectively
  • Both have long chains of sugars joined by a-1,4
    linkage
  • Glycogen often branched, branch point formed by a-1,6 linkage
  • Cellulose – no branching
  • Sugars joined exclusively by b-1,4 linkage
  • Useful for structural role, most animals do not have the enzyme
    required to break
23
Q

Simple Lipids - Triglycerides

A
  • Extremely hydrophobic compounds
  • Two components - glycerol and a fatty acid
  • Glycerol is an alcohol
  • Fatty acid - long hydrocarbon chain attached to a carboxyl group
  • Fatty acid is attached to glycerol via a covalent bond between the carboxyl group of the fatty acid and a
    hydroxyl group on the glycerol
  • Fatty acids can be saturated or unsaturated
  • Saturated fatty acids have no carbon-carbon
    double bonds
  • Unsaturated fatty acids have at least 1 carboncarbon double bond
24
Q

Phospholipids

A
  • Phospholipids critical to life – also
    called complex lipids
  • Main component of cellular
    membranes
  • Consist of lipid bound to
    phosphate group
  • Phosphate attached to one of the
    -OH groups of glycerol in the lipid
  • May have additional functional
    groups bound to phosphate
25
Q

Nucleic Acids

A
  • Transmit genetic information, allows production of protein
  • Two kinds
  • Deoxyribonucleic Acid (DNA)
  • Responsible for transfer of genetic information
  • Harbors coding information for all proteins
  • Ribonucleic Acid (RNA)
  • Transcribes genetic information
  • Allows cellular machinery to make proteins
  • Both are composed of nucleotides
26
Q

Nucleotides

A
  • All have 3 components
  • Phosphate
  • 5 carbon sugar (ribose
    or deoxyribose)
  • Nitrogenous base
  • Two classes of
    Nitrogenous bases
  • Purines (Adenine and
    Guanine)
  • Pyrimidines (cytosine,
    thymine, and uracil)
27
Q

Joining of Nucleic Acids

A
  • Nucleotides assembled into DNA or RNA via
    phosphodiester linkage
  • 5’ phosphate from one covalently bound to 3’
    hydroxyl of ribose (or deoxyribose) of next nucleotide
  • Order in which deoxynucleotides are added
    determines genetic information carried
28
Q

DNA vs. RNA

A
  • DNA – bearer of genetic information
  • Only represents information
  • Cannot do anything
  • RNA essential for realizing potential of DNA, converts into molecules that can perform
    cellular “work”
  • Three types of RNA required
  • mRNA – transcripts
  • tRNA – delivery of amino acids to the ribosome
  • rRNA – catalytic component of ribosome
29
Q

Proteins

A
  • Proteins - the machines that run the cell
  • Enzymes are proteins
  • Catalyze most biological reactions
  • Reactions essential for life of cell
  • Proteins have building blocks
  • Amino acids - monomers of proteins, all have same basic structure
  • Joined together via peptide bonds
30
Q

Structure of Amino Acids

A
  • 20 different amino acids
  • Basic structure for all the same
  • Only variable is side chain
  • 3 classes of side chains - polar,
    charged, hydrophobic
  • All 20 amino acid side chains
    are distinct - confer different
    properties/reactivity
  • Allows for extreme diversity in
    structure/function of proteins
31
Q

Types of Isomers

A

Structural Isomers - different covalent arrangement
of atoms
Geometric Isomers - identical in arrangement of
covalent bonds, different spatial orientation of
groups
Enantiomers - mirror images of each other, cannot
be superimposed, gives molecules “handedness”,
all amino acids have enantiomers

32
Q

Protein Structure

A
  • Four levels of Protein Structure
  • Primary
  • Secondary
  • Tertiary
  • Quaternary
33
Q

Primary Level of Polypeptide Structure

A
  • Amino acids - linked together by peptide bonds
  • Several amino acids joined together make a polypeptide
  • The order in which the amino acids are joined together is
    the PRIMARY LEVEL OF PROTEIN STRUCTURE.
34
Q

Secondary Level of Protein Structure

A
  • Polypeptide chains can fold into 2 conformations -a-helix, bpleated sheet
  • a-helix - coiled structure, like a
    slinky or a corkscrew
  • Structure formed and
    maintained by hydrogen
    bonding
  • Bonds between amine and
    carboxyl groups of amino acids
    in successive turns of coil
35
Q

Secondary Level of Protein Structure cont

A
  • Polypeptide chains can fold into 2 conformations - a-helix, b-pleated sheet
  • b-pleated sheet - flat structure , due to
    polypeptide chain folding back towards itself,
    draw on board
  • Structure also formed and maintained by
    hydrogen bonding
  • Bonds between amine and carboxyl groups of
    amino acids of different regions of chain folded
    back on its self
36
Q

Tertiary Level of Protein Structure

A
  • Overall shape of protein molecule
  • Forms when secondary structures interact
    with each other
  • Tertiary structure occurs when:
  • Two or more a-helices interact
  • Two or more b-pleated sheets interact
  • Any number of a combination of both ahelices and b-pleated sheets interact
37
Q

Tertiary Level of Protein Structure cont

A
  • Held together by a number of
    interactions
  • Ionic bonds
  • Hydrogen bonds
  • Disulfide bridges
  • Hydrophobic interactions
38
Q

Quaternary Level of Protein Structure

A
  • Occurs when two or more different
    polypeptides interact
  • Same types of interactions that
    stabilize tertiary interactions also
    stabilize quaternary interactions
  • Ionic bonds
  • Hydrogen bonds
  • Disulfide bridges
  • Hydrophobic interactions
39
Q

Protein Denaturation

A
  • Loss of protein activity, may be permanent or transient
  • Due to loss of secondary, tertiary,
    and/or quaternary structure
  • May be induced by chemicals –
    chaotropic agents (urea)
  • May be induced by physical means –
    heat or desiccation
  • Some proteins renature (refold)
    spontaneously, need only relieve cause
    of denaturation
  • Others require assistance – chaperones

Microbio (6 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions