chp 5 Flashcards
(161 cards)
1
Q
complex group of macromolecules . who ?
A
proteins
2
Q
proteins are polymers of how many amino acids ?
A
20
3
Q
name a protein that is found in the RBC
A
hemoglobin
4
Q
Are amino acid polymers of 50 or fewer considered peptides?
A
yes
5
Q
polymers of amino acids greater than 50 are considered wt ?
A
proteins or polypeptides
6
Q
wdwm by amphoteric ?
A
both acid and base
7
Q
NH3 is considered amphoteric true or false ?
A
true
8
Q
wt do we call the amino acids with both positive and negative charges and have zero net charge at ph 7
A
zwitterions
9
Q
wt are the 4 types of amino acids ?
A
non-polar , neutral polar , acidic and basic amino acids
10
Q
wt type of interactions do non polar form ?
A
hydrophobic interactions
11
Q
how do neutral polar amino acids interact with water ?
A
through hydrogen bonding
12
Q
wt do neutral group contain ?
A
hydroxyl group or amide group
13
Q
wt are examples of hydroxyl group
A
serine , threonine , and tyrosine
14
Q
examples of amide group
A
asparagine and glutamine
15
Q
acidic amino acids have wt ?
A
carboxylate group (negative charges
16
Q
wt do they have basic amino acids
A
side chains of amino group ( positively charges )
17
Q
example of a weak base
A
histidine
18
Q
wt are the functions of amino acids ?
A
1- components of proteins
2-chemical messengers
3-building blocks
4-plays a key role in metabolic pathways
19
Q
wt is the primary function of amino acids ?
A
components of proteins
20
Q
what type of chemical messengers do amino acids act like
A
1- neurotransmitters and 2- hormones
21
Q
wt is a thyroxine ?
A
a tyrosine derivative hormone produced in the thyroid gland and regulates metabolism
22
Q
wt is a melatonin
A
a hormone that regulatesnight-day and sleep wake cycles
23
Q
wt is a gaba ?
A
a neurotransmitter
24
Q
who secrets gaba
A
pancreas secretes it with insulin
25
wt is a serotonin
a neurotransmitter stabilizes our mood and feelings
26
how is amino acids involved in urea cycle ?
it helps in removing rexcess nitrogen from the body by converting it into urea for excretion
27
how does γ-Carboxyglutamate in prothrombin works ?
basically prothrombin is a protein that helps ur blood clot , one of its amino acids is changed to y -carbo... , which allows the protein to attach to calcium , helping it work properly in the clotting process
28
how does 4-hydroxyproline and 5-hydroxylysine in collagen works ?
collagen fives ur skin , bones and other tissues their strength and some structure some of its amino acids become 4- and 5 ... which helps the collagen hold its shape
29
how does Phosphorylation of serine, threonine, and tyrosine works ?
three types of amino acids , adding small chemical group called a phosphate can turn a protein on or off or change its function
30
wdwm by structural isomers ?
same molecular formula , diff structures
31
give me and example of structural isomers
aldehydes and ketones
32
wdwm by stereoisomers ?
same molecular formula and same structural formula but the atoms are arranged differently in 3d space
33
wt are the two main types of stereoisomers ?
geometric and optical
34
wdwn by geometric structures
it occurs with molecules that have a carbon - carbon double bond , each carbon has two diff groups attached and we either have a cis or trans isomer
35
wdwm by cis and tran ismoer
cis ismoer , two similar groups are on the same side of the double bond both top or both bottom , trans isomer , the two similar grouos are on opposite sides of the double bond
36
cis and trans isomer are an example of wt ?
geometric steroisomers
37
if the carbon atom in the double bond are polar ( like charges ) they are wt ?
a more stable cis ismoer
38
wdwm by optical steroisomers ?
these isomers involve molecules that have a chiral carbon and these moleculers can rotate plane - polarized light
39
wdwm by chiral carbon
where the carbon is attached to four diff groups ( center carbon )
40
in an optical stero D is left or right ?
right whcih means +
41
the rotation of optical stereo is measured using which device ?
polarimeter
42
wt are the types of optical stereoisomers ?
enantiomers , diasteroisomers and epimers
43
wdwm by enantiomers ?
miror images ismoers , like ur left and right hand they are non-superimposable
44
wdwm by Diastereoisomers ?
they are non mirror image ismoers , they differ in their arrangement of atoms
45
wdwm by epimers ?
a type of Diastereoisomers where the only diff is at one specifc chiral carbon
46
which amino acid is the only nonchiral standard mino acid ?
glycine
47
L-Alanine and d-alanine are wt ?
mirror images of each other. or ENANTIOMERS
48
which amino acids are only found in proteins D OR L ?
L-amino acids
49
wdwm by pl - isoelectric point ?
the ph at which amino acid has no net charge this means the negative and positive charge they balance out each other
50
when the amino acid is at pl it exists as ?
zwitterion
51
wt are the two important main groups of amino acids ?
amino group ( NH2) and carboxyl group (COOH )
52
wt happens to the amino acids at diff ph levels
at low ph , the amino acid is more likeyly to be protonated ( h+ gains ) so posiyive charge at hgih ph the amino acid will lose more hydrogen ions becoming negatively charged
53
wt is pl ?
when amino acids has no overall charge
54
if the ph is below the pl , wt is the charge of the amino acid ?
positively charged
55
if the ph is above the pl wt is the charge of amino acid
negatively charged
56
when the amino acid is neutral wt is the pl ?
pl is the ph
57
pl is used for wt ?
separate and purify proteins
58
wdwm by The pKa values
points at which the groups go from being protonated to deprotonated
59
wt do we call the pka values on titration curve ?
inflection point
60
wt are the two main important chemical reaction of amino acids ?
1- peptide bond formation
2-disulfide bridge formation
3- schiff base formation
61
wdwm by peptided bond formation ?
a type of bond that forms bw two amino acids to link them together into polypeptide chain or protein
62
during the formation of peptide bond it undergoes wt type of reaction
dehydration reaction , the removal of water
63
how does dehydration occurs ?
the mino group ( NH2) of one amino acid react with the carboxyl group ( COOH ) of another , a water molecule is removed from the reaction ( we call this the dehydration part) and then peptide bond ( C-N ) forms bw two amino acids
64
dehydration at the end forms wt bw the two amino acids ?
dipeptide is formed
65
wt is a disulfide bond ?
a type of covalent bond from bw two cysteine amino acids , cysteine has a special group called a thiol group (SH)
66
wt happens in the disulfide bond ?
causes a dehydrogenation (oxidation )
67
wdwm by dehydrogenation ?
a hydrogen atoms are removed from the cysteine side chains causing the two cysteine molecules to form a disulfide bridge (s-s)
68
why is disulfide briges important ?
important for the three dimensional shape of proteins because it helps stabilize the proteins structure and IMPORTANT IN PROTEIN FOLDING
69
Peptide bonds are amide
linkages formed by who ?
nucleophilic
acyl substitution
70
wt is schiff base ?
a type of bond that forms when a primary amine (NH2) group reacts with carbonyl group (C double bond O )which can be part in either an aldehyde or ketone
71
schiff base IS IMPORANT in wt ??
enzyme reactions , biological processes and some types of protein modifications
72
which terminal has the free amino group (NH2) ?
N terminal
73
which terminal has the free carboxyl group (COOH)
C terminal
74
which aino acid is the n terminal
first amino acid
75
whcih amino acid is the c terminal ?
last
76
wt is the charescteristic of the peptide bond ?
rigid and flat
77
wt is a glutaothione ?
a type of peptide but it is tripeptide made from GULTAMATE AND CYSTEINE AND GLYCINE
78
glutaothione plays a role in wt ?
protein and dna synthesis , metabolism of toxic subs and amino acid transport
79
wt is Vasopressin
Vasopressin is a nonapeptide It is an hormone produced in the hypothlamus that regulates water balance, affects appetite, and influences body temperature.
80
wt is a Oxytocin?
Oxytocin is another nonapeptide hormone involved in uterine contractions during labor and lactation t also plays a role in social bonding and emotional regulation.
81
Oxytocin,Vasopressin and Glutathione is a type of wt ?
a type of peptide
82
wt are the functions of proteins ?
catalsis , structure , movement , defense , regulation , transport , storage and stress response
83
who breaks down starch into sugars in ur digestive system
amylase
84
wdwm by globular proteins ?
are spherical shape and water soluble ,
85
in wt is the globular proteins involved in ?
catalysis and regulation and transport
86
wdwm by fibrous proteins ?
they have more elongated or fibrous shape and usually INSOLUBLE IN WATER
87
fibrous proteins are involved in wt ?
structural support and strength
88
wdwm by simple proteins
consists of only amino acids
89
example of simple proteins
albumin and globulin
90
wdwm by conjugated proteins
consist of protein components and one or more non protein components we call the non protein parts PROTHETIC GROUPS
91
prosthetic groups could be wt ?
lipoproteins , glycoproteins and hemoproteins
92
The structure of a protein is organized into four levels:
primary, secondary, tertiary, and quaternary
93
wdwm by the primary structure (the sequence ) ?
the sequence of amino acids in the protein held together by peptide bonds .Changing even one amino acid in the sequence can change how the protein works.
94
wdwm by Secondary Structure (Local Folding)
is how parts of the protein chain fold into certain shapes due to hydrogen bonds between the amino acids.
95
wt r the two main types of secondary structures ?
alpha helix and beta sheet
96
diff bw alpha helix and beta sheet
alpha helix chain of amino acifd twists into a coil like a spiral staircase and BETA sheet the chain folds back on itself creating a plated zig zag pattern
97
wdwm by tertiary structure ?
the overall 3D shape of the entire protein.This shape is determined by the interactions between the side chains (also called R groups) of the amino acids.
98
wt happens in the tertiary structure ? ?
The protein folds into its final shape, and this shape is crucial because it allows the protein to interact with other molecules (like how an enzyme binds to its substrate).
99
wdwm by Quaternary Structure (Multiple Chains Together)
Some proteins are made up of multiple polypeptide chains , The quaternary structure is how these separate chains come together to form a complete protein.
100
example of Quaternary Structure
hemoglobin it is made of four subunits
101
wdwm by mutation ?
is the alterations in DNA sequences, which leads
to change in amino acid in the primary structure of
polypeptides
102
wts the diff bw Conservative vs. Non-conservative Mutations:
Conservative mutations: This happens when a mutation changes an amino acid to one that is chemically similar Non-conservative mutations: These occur when an amino acid is replaced with one that has very different chemical properties
103
where can we find Invariant residues
amino acids in a protein
104
wt happens if a mutation changed one of the amino acids of invariant residues ?
it can harm the proteins function and cause problems
105
What is Sickle Cell Anemia?
aused by a mutation in the gene that codes for the β-globin subunit of hemoglobin
106
wt is replaced in sickle cell anemia ?
the glutamic acid at position 6 of the β-globin chain is replaced by valine
107
how does the sickle shaped red blood cells affect the oxygen transport ?
dont flow smoothly through blood vessels and this leads to low oxygen levels in the bodys tissues
108
Both the alpha-helix and beta-sheet structures are held together by
hydrogen bonds
109
another name of supersecondary structures
motifs
110
wdwm by domains ?
Large proteins (with 200+ amino acids) often have domains, which are like independent functional regions within the protein
111
domains are created from ?
Domains are created by gene duplications and can be repeated in modular proteins
112
wt happens in Electrostatic Interactions (Salt Bridges):
Oppositely charged amino acid side chains (e.g., Lys and Glu) form ionic bonds that stabilize the protein.
113
wt happens in Covalent Bonds (Disulfide Bridges):
Disulfide bonds between two cysteine residues create strong covalent links
114
who helps the shape of tertiary ?
Hydrophobic interactions, salt bridges, hydrogen bonds, and disulfide bonds all help stabilize this shape
115
how does hydration ( water bridges ) help proteins ?
it helps the protein to fold and maintain its structure
116
The subunits in a quaternary structure are mostly held together by
noncovalent interactions
117
Proteins with quaternary structure are common for several reasons:
1-Efficiency in synthesis
2-Replacement of worn-out components
3-Regulation of function:
118
wt is a Allosteric regulation
when a protein's function changes due to the binding of a molecule at a site other than the protein's active site
119
how does the alloseric transition affect the protein
it causes a conformational change
120
positive cooperativity, is a type of wt ?
allostery
121
wdwm by positive cooperativity
When one oxygen molecule binds, it changes the shape of hemoglobin and makes it easier for the next oxygen molecule to bind. thats an example
122
wdwm by partially or completed unstructured
dont have a stable , well defined three dimensional shape
123
Denaturation
the process where a protein's structure is disrupted,
124
wt happens when the protein is denaturated ?
causing it to unfold and lose its function
125
which structure remains intact during denaturation ?
primary
126
Renaturation
the process of proteins refolding back into their functional shape
127
Several conditions can cause denaturation:
Strong acids or bases (affecting ionic and hydrogen bonds)
Changes in temperature (disrupting hydrophobic and hydrogen interactions)
Organic solvents (affecting polar and non-polar interactions)
Reducing agents (break disulfide bonds)
Detergents (disrupt hydrophobic interactions)
Salt concentration (disrupts ionic bonds)
Heavy metals (like Hg²⁺ or Pb²⁺, which bind and disrupt ionic interactions)
Mechanical stress (like stirring or grinding
128
Protein folding
process where a polypeptide chain folds into its functional 3D structure based on its primary sequence
129
Small proteins with less than 100 amino acids , how do they fold ?
directly into their final structure
130
how do large proteins fold correctly ?
need intermediate stages ( molten globules )
131
wt do Molecular chaperones do ?
help with protein folding by preventing incorrect interactions and ensuring proper folding
132
Molecular Chaperone are considered wt ?
proteins that help proteins fold correctly
133
can chaperons help misfolded proteins to fold correctly ?
yes
134
Types of chaperones:
Ribosome-Associated Chaperones
Hsp70s: Bind and stabilize proteins during early folding stages.
Hsp90s: Assist in later folding steps.
Chaperonins: Form complex structures to facilitate faster folding.
135
If proteins are misfolded and form insoluble aggregates, it can lead to diseases like
Alzheimer's or Huntington's disease
136
Proteins can be classified based on their solubility in water into two main categories:
fibrous proteins and globular proteins.
137
These proteins are typically structural, and they are not soluble in water. They often contain large proportions of α-helices and β-pleated sheets talking abt who ?
fibrous proteins
138
wt are the three fibrous proteins ?
keratin , fibroin , collagen
139
keratin made from wt ?
It has a double α-helix
140
fibroin is a protein made from wt ?
B sheets
141
wt does collagen contain ?
has a triple α-helix structure and contains high amounts of glycine and proline
142
globular proteins are water soluble or insoluble ?
water soluble
143
subclasses of Globular Proteins:
myoglobin , hemoglobin , enzymes , immunoglobulins and peptide hormones
144
Hemoglobin and Myoglobin
These are oxygen-binding proteins that contain a heme prosthetic group that binds oxygen. They are involved in the transport and storage of oxygen in the body.
145
where is myoglobin found ?
muscle tissue
146
how many a helix does myoglobin has ?
8 and holds one heme group
147
myoglobin is used for wt ?
to store oxygen for when oxygen levels are low
148
where is hemoglobin found ?
red blood cells , hemoglobin is made up of 4 subunits
149
hemoglobin
oxygen transport from lungs to tissues
150
Immunoglobulins
These proteins are part of the immune system and help defend the body by binding to and neutralizing pathogens like viruses and bacteria
151
hemoglobin is composed of how many a and b chains ?
4 in total 2 a and 2 b
152
we have two states of hemoglobin
T and R
153
wdem by t state ?
deoxygenated hemoglobin , in this state less efficent in binding oxygen
154
r state ?
oxygenated hemoglobin
155
wdwm by Cooperative Binding
means that when one oxygen molecule binds to hemoglobin, it causes a conformational change that makes it easier for additional oxygen molecules to bind. This creates a sigmoidal (S-shaped) curve on the oxygen dissociation graph.
156
when ph decreases wt happens to the hemoglobins affinity for oxygen ?
decreases , which makes it easier to release oxygen to tissues
157
wdwm by BOHR EFFECT ?
When the pH decreases (increased [H+], i.e., more acidic environment), hemoglobin's affinity for oxygen decreases, making it easier to release oxygen to tissues
158
wt causes bohr effect ?
This happens because the higher [H+] concentration (due to factors like CO2 being produced in tissues) shifts hemoglobin toward the T state, favoring oxygen release
159
if the temp is high wt happens to HAFO ?
decrease which helps release more oxygenn to tissues
160
2,3-Bisphosphoglycerate (BPG)
molecule in red blood cells that lowers hemoglobin’s affinity for oxygen. This helps hemoglobin release oxygen more efficiently when oxygen levels are low.
161
BPG in red blood cells how does it affect the oxygen affinity ?
it lowers oxygen affinity
