egzam 1 cb Flashcards
1
Q
Polymers of polysaccharides, fats, and proteins are all synthesized from monomers by
A
CONDENSATION/dehydration Reaction (removing H2O)
2
Q
Mitochondria was likely a _____ bacteria that got engulfed by a ______ cell.
A
aerobic; anaerobic
3
Q
SNUD
A
saturated- no double bonds, unsaturated- double bonds
4
Q
Smooth E.R
A
synthesizes fatty acids, phospholipids and cholesterol
5
Q
Rough E.R
A
synthesizes proteins
6
Q
Where are polysaccharides made?
A
Golgi Apparatus
7
Q
How is carbon able to bond to 4 atoms?
A
by combining 2 orbitals (s & p)
8
Q
All amino acids except ____ are Asymmetrical
A
Glycine
9
Q
Mitochondria are present in all
A
Eukaryotes (plants and animals)
10
Q
Cellular Respiration uses____ and produces ____
A
sugar; ATP
11
Q
Whats the order they evolved in?
A
Anaerobic Prok
Anaerobic Euk
Photosynthetic Prok
Aerobic Prok
Aerobic Euk
Photosynthetic Euk
12
Q
List the nonpolar forces
A
LDS, VW, D-D
13
Q
Amino acids all have a ____ backbone
A
N-C-C
14
Q
Glycosidic bonds link
A
a Sugar and a Sugar
15
Q
A sugar linked to a base and a phosphate
A
Nucleotide
16
Q
A sugar linked to a base
A
Nucleoside
17
Q
The bond that links phosphate groups
A
phosphoanhydride bond
18
Q
The bond that links 2 nucleotides
more specifically links the 3’ carbon atom of one SUGAR molecule and the 5’ carbon atom of another SUGAR
A
phosphodiester bond
19
Q
The bond that links sugar and phosphate
A
phosphoester bond
20
Q
From top to bottom list the parts of a phospholipid
A
hydrophilic (polar) head, Phosphate, Glycerol , hydrophobic fatty acid tail (non polar)
21
Q
What is the greatest determinant whether the interaction between molecules will be transient or stable?
A
surface complementarity between molecules
22
Q
What force/bond has the greatest impact on organization of lipid molecules with long hydrocarbon tails in the membrane?
A
hydrophobic forces
23
Q
Once carbon has been turned to its most stable form, through what process can it return to its organic state?
A
photosynthesis
24
Q
NADH and NADPH both carry two additional __________ and one additional __________.
A
2 electrons; 1 proton
25
How can you rank how oxidized molecules are?
The more O2 it has (less H+)
26
A positive +ΔG means the reaction is spontaneous or nonspontaneous?
Nonspontaneous
27
How do enzymes effect reactions?
they reduce the activation energy
28
True or false: Enzymes are not permanently altered by the reactions they catalyze
True
29
What is the DNA backbone made of?
sugar & phosphate
30
What 4 things are attached to the alpha carbon?
1. a hydrogen
2. an R group
3. an amino group
4. a carboxyl group
31
Only ___-amino acids are found in proteins
L
32
What are the two kinds of R-groups?
1. Nonpolar/ hydrophobic
2. Polar/ hydrophillic (can be CHARGED)
33
Uncharged yet polar amino acids tend to be found where?
On the surfaces of proteins
34
Acidic amino acids have what characteristic?
negative charge
35
Basic amino acids have what characteristic?
positive charge
36
True or false: Polypeptides have directionality
True
37
What is the amino group end of a polypeptide called?
N-terminus
38
What is the carboxyl group end of a polypeptide called?
C-terminus
39
What are the subunits of DNA and RNA called?
nucleotides
40
Base pairs are joined by what?
hydrogen bond
41
What are the 2 types of nucleic acids?
DNA and RNA
42
What kind of enzyme adds a phosphate group to another protein?
kinase
43
Purines include which 2 bases?
A & G
44
Pyrimidines include which 3 bases?
T & C & Uracil
45
What's the difference between deoxyribose and ribose?
Deoxyribose lacks an Oxy on the 2′Carbon.
46
DNA backbones run in what direction
5'-3' antiparallel
47
The nitrogenous bases are linked by what bonds?
hydrogen
48
The 3D shape of a molecule is influenced by ___________ interactions
intramolecular
49
The specific shape of the macromolecule is influenced by _______ bonds.
Whereas the shape of a protein is determined by _____________.
hydrophobic;
amino acid sequence
50
High levels of ____ are needed to complete chemical reactions
Heat
51
What is the sum of all the chemical reactions occurring in the cell?
Metabolism
52
What do catabolic reactions release?
energy
53
What is the 2nd Law of Thermodynamics?
Every energy transfer/transformation increases the entropy of the universe
54
What is the First Law of Thermodynamics?
Energy can not be created or destroyed
55
Photosynthesis equation
CO2 + H2O --> O2 + Sugar
56
Cellular Respiration equation
O2 + sugar --> CO2 + H2O
57
True or False: In oxidation & reduction reactions 2 atoms do NOT form a polar covalent bond
False, a polar covalent bond occurs
58
Adding hydrogen to a carbon atom is an example of what
reduction
59
Removing hydrogen from a carbon atom is an example of what
oxidation
60
Adding oxygen to a carbon atom is an example of what
oxidation
61
Electrons are shifted away from the carbon, and the carbon atom becomes progressively more _______
oxidized
62
What is Gibbs free energy?
Amount of energy in a system available to do work
63
Y--> X
If the free energy of Y is greater than the free energy of X, is delta G positive or negative, and will the rxn occur spontaneously?
Reactants>product
would mean that there'll be excess energy released. Exergonic rxns release energy. The delta G would be negative and hence the rxn is spontaneous. (this is favorable)
64
X--> Y
If the free energy of Y is greater than the free energy of X, is delta G positive or negative, and will the rxn occur spontaneously?
Product>Reactant
would mean that there'll be energy consumed. Endergonic rxns use energy. The delta G would be positive and hence the rxn is nonspontaneous.
65
Enzymes reduce the energy needed to initiate (spontaneous or nonspontaneous?) reactions
spontaneous
66
What do enzymes do during a chemical reaction?
stabilize the transition state (the high energy intermediate) and lower the activation energy
67
T/F: Enzymes help regulate metabolic pathways
T
68
Energy released by energetically favorable reactions can be stored as chemical bond energy. What does the cell use to store this energy?
activated carriers (ex. ATP, NADH, NADPH)
69
ATP supplies the energy for a cell to do work. Give one example of this
-Transport materials across membranes (pumps)
-Molecular motors
70
The terminal phosphate of ATP can be readily transferred to other molecules. What is this process called?
phosphorylation
71
In activation, ATp transfers a ____ to a molecule in order to produce a ________.
phosphate ; intermediate
72
Removal of electrons from an atom is called
Oxidation
73
Adding electrons to an atom is called
Reduction
74
NADP+ is the ______ electron carrier. When it gains an H+ it becomes NADPH and is now the ______ agent for ______ reactions.
oxidized;
reducing agent; anabolic
75
NADH is the ______ electron carrier. When it loses an H it becomes NAD+ and is now the ______ agent for _______ reactions.
reduced;
oxidizing agent; catabolic
76
NAD+ is the _______ agent for ________ reactions.
oxidizing; catabolic
77
NADPH is the ________ agent for _______ reactions.
reducing; anabolic
78
Glycolysis is an example of what kind of reaction? Also is NAD+ involved?
(it's the breaking down of glucose into 2 pyruvate)
catabolic; yes
79
T/F !! Acetyl CoA is an activated carrier involved in metabolism !!
True, now repeat it
80
Biotin is an example of a what?
activated carrier
81
What does Biotin actively carry (aka transfer)?
the carboxyl group
82
Condensation rxn vs Hydrolysis rxn: What's the difference?
Condensation rxns JOIN together 2 things by removing an H2O
Hydrolysis rxns BREAK bonds by adding an H2O
83
Where does the energy for the synthesis of macromolecules (polypeptides, polysaccharides, nucleic acids) come from typically?
the hydrolysis of nucleoside triphosphate
84
During the synthesis of macromolecules, what else is made during the process?
a high energy intermediate
85
How does a nuclei acid chain grow? Give steps
Start off with the existing DNA strand. A triphosphate nucleotide is added, but 2 phosphates are broken off to be used as energy. The nucleotide (still has a phosphate) attaches to the DNA strand.
86
Polypeptide backbone
N-C-C
87
The shape & function of a protein is specified by
its amino acid sequence
88
What gives a protein its distinct and individual properties?
the R group
89
What bonds hold polypeptides together?
Noncovalent (V.W, hydrogen bonds)
90
Polypeptides fold into the conformation that has _____?
lowest energy
91
In an aqueous environment, the polypeptide chain will fold to keep the _____ side chains on the inside and the _____ side chains on the outside.
nonpolar; polar
92
Where in a protein can you find hydrogen bonds? (3 places)
backbone- backbone (btwn N-H "amino" & C-O "carboxyl")
backbone - side chain
side chain - side chain
93
Proteins fold into the conformation that has _______?
lowest energy
94
If a protein is denatured by urea what will the protein do if urea is then removed?
return to its original shape
95
What do Chaperone proteins do?
guide the folding of new polypeptides
96
Some chaperone proteins can act as an isolation chambers. Explain this
the chaperone protein is like a container. It catches the newly formed polypeptide and puts it inside of itself allowing it to fold correctly. Once it does, the cap lifts and the protein is released.
97
Primary structure
amino acid chain (polypeptide)
98
Secondary Structure
Polypeptide gets folded into helices or pleated sheets
99
Tertiary Structure
3D folding due to the side chain interactions
100
Quaternary Structure
protein with at least 2 polypeptide chains
101
Certain amino acids tend to form α helices while others dont. What's one thing that can lead to destabilization of α helices?
the R group being too big or too small
102
In proteins, α helices are almost always _______ (for some reason)
right-handed
103
Transmembrane proteins have _________ic amino acid side chains.
hydrophobic
104
α helices are found in transmembrane proteins such as receptor and transport proteins. oK? ok.
repeat it
105
Why do α helices wrap around each other?
to minimize the exposure of hydrophobic side chains to the aqueous environment
106
What causes the "pleat" of the β- pleated sheet?
side chains which point up and down
107
How do Parallel vs Antiparallel β-sheets differ?
Parallel - the polypeptides are running in the same direction
Antiparallel- the polypeptides run in opposite directions
108
Beta sheets occur due to _________ between the amine (NH) and carboxyl groups (CO) of the polypeptide backbone, thus making it very strong.
hydrogen bonds
109
Amyloid structure is just stacked _________
β-sheets
110
α-helices and β-sheets make up around __% of a protein's secondary structure
50%
111
How are α-helices and β-sheets connected?
looped regions that change the direction of the protein strand
112
Chloroplasts have their own ____ & _____, just like mitocondria.
DNA & ribosomes
113
Chloroplasts likely arose from ______ bacterium getting engulfed by a _______
photosynthetic; aerobic
114
What is a protein domain?
a folded unit of the tertiary structure typically with a certain function
115
T/F: Solvents dont break all noncovalent bonds
false
116
A protein ______ is the modular unit from which many larger single-chain proteins are
constructed
domain
117
Any substance that will bind to a protein is known as its ______.
ligand
118
Enzymes bind the _______ (or inhibitors) at their active site. Active site is ON the enzyme!!
substrates
119
The high-energy intermediate is called the _______
transition state
120
If two species have the same amino acid sequences do the 2 different proteins serve the same function?
yes, since the structures are the same.
121
Substrates bind to the ________ of an enzyme.
active site
122
An allosteric inhibitor does what?
changes the shape of an enzyme-
123
What is feedback inhibition?
when an enzyme's activity is inhibited by its end product
124
The architecture and function of a polysaccharide are determined by _____ and _____.
sugar monomers
positions of glycosidic linkages
125
Hydrolysis of glycogen releases ______
glucose
126
In aqueous solutions, many sugars form ______ through interactions btwn hydroxyl and carboxyl groups
rings
127
Whats the most stable form of glucose
d-glucose
128
The formation of a ring by d-glucose can result in two alternative forms.
These forms depend on the ________ of the _______ group on carbon number 1
orientation; hydroxyl
128
The formation of a ring by d-glucose can result in two forms what are they?
α d-glucose (hydroxyl group downward)
β d-glucose (hydroxyl group upward)
128
NADPH is involved in anabolic processes. Give one example of a anabolic reaction.
photosynthesis
129
α-helices and β-sheets are stabilized by what bonds?
hydrogen bonding
130
_________ is a common way to regulate protein activity. Adding one will turn it on, and removing one will stop the activity.
phosphorylation
131
2 polypeptides can be linked by ______ bonds.
disulfide
132
cysteine and disulfide bonds are involved in ________ structure
tertiary
133
What is Km and what does it tell us?
The substrate concentration at which enzymes work at half the max velocity. Km tells us how strongly a substrate is bound
134
Antibodies are made of _________
4 polypeptides, 2 heavy chains & 2 light chains
135
Vmax
the max rate of the enzymatic reaction. Is reached when the enzyme is saturated
136
What bonds hold the light and heavy chains together?
disulfide
