Font size
WorksheetsPart 3 - Intro to biochem MCQ
Total questions: 146
Worksheet time: 1hrs 13mins
Which is the energy of motion?
Kinetic
Potential
Energy is the capacity
To supply heat or do work
To withdraw amines
To eat up tasty pancakes
Why do chemical reactions occur?
The amount of energy in a substance is important
To stabalize chemical reactions
Because..
Potential Energy is...
Stored Energy
Motion
Larger mass + velocity = More Kinetic Energy
True
False
SI unit of Energy:
J (Joules)
(Julian Lennon)
mol/L
KJ
Potential + Kinetic Energy = always constant
Yes
No
Hmm
Thermal Energy is...
is the kinetic energy of molecular motion, which we measure by finding the temperature of the object.
is the potential energy of molecular motion, which we measure by finding the temperature of the object.
Idk
Heat is
is the amount of kinetic energy transferred from one object to another as the result of a temperature difference between them.
is the amount of potential energy transferred from one object to another as the result of a temperature difference between them.
Sausage?
Chemical Energy is...
is a kind of kinetic energy in which chemical bonds act as the ‘storage’ medium.
is a kind of potential energy in which chemical bonds act as the ‘storage’ medium.
First law of thermodynamics is...
The total internal energy of an isolated system is constant
The total internal energy of an open system is constant
The total internal energy of an isolated system is variable
Enthalpy is..
The total internal energy change of a reacting system is given by ΔH, which is the enthalpy change of the system.
Type
Exothermic reaction...
Heat is released
Heat is consumed
Endothermic reaction is...
None of the above
Heat is released and is non-spontaneous
Heat is absorbed and is non-spontaneous
Heat is absorbed and is spontaneous.
A Catalyst is a substance that speeds up a chemical reaction without being chemically changed itself.
True
False
Endothermic is energy required when a bond is made
True
False
Is the order of entropy increasing here:
Solid --> aqueos --> Liquid --> Gas
False
True
Entropy is..
is a measure of the amount of molecular randomness or disorder in a system.
Randomness..
Is Gibbs Free Energy negative at spontaneous reactions?
Yes
No
Gibbs free energy is spontaneous only when entropy is negative, and enthalpy is positive
True
False
Rate of reverse = Rate of forward is..
Dynamic Equilibrium
Some German Dude
Are forward and reverse reactions still happening at equilibrium?
Yes
Nay
Closed system is required for equilibria
Nop
Yep
Precipitation could possibly shift a reaction to become irreversible
Yep
No!
What affect K constant
Temperature
Pressure
Concentration
If Kc value is large..
Product favoured
Reactants favoured
Favor* Because Americanism
Acid donates protons (H+) and Base accepts them
Yes
No
Conjugate acid-base pairs differ by one proton
Yepy
Nopy
For a molecule to accept proton, it has to have one unshared electron
Ye
No
Weak acid/base has
Partial dissociation in water
Full dissociation in water
Higher Ka, stronger acid
Yes
Yesn't
Difference in pH is 10 fold difference in H+ conc.
No
Ye
High pH = High H+
NO
YESS!
Indicators change color over small pH ranges
Ye
No
low pKA = stronger acid
Yes
No
Hasselbach-Henderson is equation to determine changes in weak acids/bases
Yes
No
Buffers consists of weak acid and its conjugate base
Yes
No
pKa also corresponds to the pH of max capacity
Yes
No
Higher Conc = Higher buffering range
Ye
No
Functional group is
is an atom or group of atoms that exhibits the same properties in all compounds that contain it.
Nay
Most naturally occurring optical isomer is..
L
D
Low alkane carbons (C1-C4) are easily broken (turned to gas) than more carnon (C16+)
Ye
No
Most common oxidation of alkane is combustion
Ye
No
Alkenes are more reactive than alkanes due to C=C bond.
Ye
No
Alkenes tend to get addition reactions from double bond
Ye
No
Reduction/Hydrogenation is (such as from oil to fats)..
Conversion of alkane to alkene
Conversion of alkene to alkane
Polymerisation is repeated chains of alkenes
Y
N
Alkyne conversion to alakane is
Hydrogenation
?
Arenes are unsaturated and delocalized electrons spread evenly
Y
N
General formula of alcohol is R-OH
Y
N
Alchohol undergo oxidation reaction to form other functional groups:
Primary alcohol --> aldehydes --> Carboxylic acid
Secondary alcohol --> Ketone
Tertiary Alcohol --> No reaction
Y
N
Carboxylic is a weak acid. When reacts with base, it forms water and salt (name changes to oate).
Y
N
Carboxylic acid + alcohol = Ester + H2O
Y
N
Esters named from parent group (Alkyl alkanotes)
Y
N
Amine - general formula is R-NH2
Y
N
Amines are basic and alkaline. Reacts with water to form salt
Y
N
Carboxylic reacts with amine to form amides and water. Amides linkage holds amino acids
Y
N
Aldehydes (C-R-R) "name ends in "al""
Ketone (C-R-H) "Name ends in "one""
Y
N
Yeye
B
Aldehydes and Ketone tend to have addition reactions (addition of Hydrogen), aldehydes is primary alcohol, while ketone is secondary alcohol.
Y
N
Carbohydrate sugars tend to have several alcohol groups and either aldehyde or ketone..
Y
N
Glycine is R=H
Y
N
Zwitterion - having separate positively and negatively charged groups
Y
N
Oils are liquid at room temperature, and fats are solid. Both are esters of glycerol.
Y
N
3 Carboxylic acids group can form linkage with each glycerol to form triester
Y
N
Triesters found in natural oils and fats usually contain different 3 acids
Y
N
Phospholipids are diester with phosphate group on the other OH group
Y
N
There are 3 main different types of isomerism
Structural isomerism
Geometrical isomerism
Optical isomerism
Y
When there is C=C bond in geometrical bond, there is no free rotation.
Y
N
L is clockwise rotation while D is anti-clockwise
Y
N
Amino acids exist in L form (few exceptions) and sugars only exist in D form
N
Y
Proline is the cyclin amino acids responsible for introducing turns in tertiary structure
N
Y
Primary - polypeptide chain bonded by peptide bonds
Y
N
Secondary - Polypeptide chain folded by beta and alpha sheet helices and bonded by Hydrogen bonds
Y
N
Tertiary Structure- One polypeptide chain folded into 3D structure
Y
N
Quternary structure - more than one polypeptide chain folded and held by non-covalent bond
Y
N
H bond required for protein folding
Y
N
Proteomics is..
Study of all proteins expressed by an organism at any time
<
Most amino acids are optically active (able to rotate plane polarised light) due to chiral/assymetry of C as it is bonded to 4 different types of atoms/groups.
Y
N
Amino acids are enantiomers (mirror images exist, opposite rotation of polarized light). Amino acids in proteins are L-form, but in bacteria (D-form)
N
Y
Hydrophobic AA's are Aliphatic or Aromatic (ring structure)
N
Y
Glycine is simplest amino acids, and the only one that is not optically active because of the 2 H bonded to C
N
Y
More carbon in hydrocarbon chain = more hydrophobicity
Y
N
Aromatic has pi electron interactions and tyrosin as donor and acceptor but tryptophan as donor only
Y
n
Pi electron is non-covalent attraction in rings
Y
N
Trytophan consume most UV light and # of trytophan = # of proteins
Y
N
Basic (Hydrophilic) amino acids contain nitrogen in side chains
Y
N
Acidic (negatively chard) contain carboxyli in side chain
Y
N
Isoelectric when pH=0.
If if H+> then it accepts H+
If H+< then it donates H+
Y
N
Smaller pK = more acid
Y
N
Histidine is buffering amino acid as when protein pKa = 7
Y
N
Angstrom used to describe distance of electrostatic bonds
Y
N
•3 types of non-covalent bond
•Electrostatic bonds
•Hydrogen bonds
•Van der waals bonds
y
n
Atom bonded with hydrogen covalently (OH,ON, OF) is donor while others are acceptors. Only Oxygen and Nitrogen act as hydrogen donor/acceptor.
N
Y
Bond length - donor to acceptor distance
Y
N
Strong hydrogen is straight, directional bond is weak hydrogen because it isn't straight.
Y
N
Amide and Hydroxyl containing amino acids and are H-bonds acceptor and donor.
Y
N
Sulphur is hydrophobic and weak!
Y
N
sulfhydrl groups oxidate to disulphide bridges
Y
N
Proline is cyclin amino acids, has secondary amine (two carbons bonded to amine group). This is a secondary amino acids that introduces turns in secondary structure in proteins, key in protein folding.
Y
N
•Hydroxyproline and hydroxylysine important for crosslinking in Collagen
• Carboxylation important in blood clotting – attachment of clots
Y
N
Nitrogen balance is essential to prevent N loss. If N intake>N growth is from pregnancy and growth while N intake<N growth from surgery, fevers, etc
Y
N
Essential amino acids aren't produced by body, Histidine/Arginine needed for child growth!
Y
N
Vegeterians lack lys, met and cys.
Indeed
F
•Severe acute malnutrition
•Marasmus – lack of overall food intake, muscle wasting due to low protein
•Kwashiorkor – lack of protein, amino acid pools are in short supply → muscle proteins maintained at expense of liver and other viscera
– oedema associated with oxidative stress
Y
N
Chinese restaurant syndome high in Glu (soy sauce eww)
Y
N
Amino acids unit in polypeptide chain is called a residue
Y
N
Peptide bond is covalent bond between 2 AAs
Y
N
Peptide bond is rigid and planar - no freedom rotation
N
Y
Freedom rotation allow to fold in different ways
Y
N
Polypeptides have a main chain (backhone) and side chain (Rn)
Y
N
•Tertiary
- folding of secondary structure elements onto themselves via side chain interactions to form compact globular structures
Y
N
Primary structure - sequence read from amino-terminal residue to carboxyl-terminal residue.
Y
N
Primary structure contains all necessary info for 3D structure
Y
N
•H-bonds are within a single polypeptide chain – intrachain
Amino acid side chains face outwards – less stearic interference
Y
N
Left-handed helix is structural component of collagen while beta sheet is structure for silk fibroin. Unlike alpha helix, beta sheets have H-bonding in different polypeptide chains (peprendicular-interchain)
Y
N
Beta turn of tertiary structure is 4 aa seperated by 3 bonds. Gamma turn is 3 aa seperated by 3 bonds.
Y
N
Central residue is proline which makes kinks, it is not found in alpha helix
Y
N
Adrenergic recptor is...
•Binds catecholamine to stimulate the sympathetic nervous system (SNS). i.e. fight-or-flight response
B
Chaperones help with protein folding
Y
N
PID - •Catalyzes the formation and breakage of disulphide bonds between cysteine residues within proteins as they fold
Y
N
Prion is protein infectious agent
Y
N
Prion Protein - alpha helix without Beta sheets
Abnormal isoform - high beta sheet.
Y
N
•Pro-proteins are turned into an active form by a post-translational modification
•Breaking off a piece of the molecule or adding on another molecule
•
•Protein precursors are often used when the protein is potentially harmful, but needs to be available on short notice and/or in large quantities
Y
N
Ehlers-Danlos syndrome
•Deficiency in collagen processing enzymes e.g. Lysyl hydroxylase
Y
N
Haemoglobin is O2 transport protein found in blood while myoglobin is found in skeletal and cardiac muscle (cytosol).
N
Y
Myoglobin (MB) has eight helices + Haem group
N
Y
The Fe2+ in myoglobin can form 2 additional bonds, one above plane of haem, and one below.
Y
N
5th coordination point of Fe2+ bind to His f8, while sixth is bind to oxygen
Y
N
O2 binding cause confromontal change where it pulls Fe2+ down to hame group.
Y
N
Myoglobin wraps around many porphyrin rings
N
Y
Myoglobin O2 binding/dissociation curve is hyperbolic (1 binding site)
Y
N
P50 is an indicator of the relative binding affinity of a globin for Oxygen
Y
N
Fe2+ binds a single molecule to oxygen, Proximal, rather than distal, His binds directly to Fe2+
Y
N
Allows the tetramer to adopt different relative positions in the absence of O2 (deoxygheamoglobin or tensed) & in its presence (oxyhaemoglobin or relaxed)
N
Y
Oxygenation of 1st haem group distors electrons around Fe2+, making it accessible to the 4 haem group.
Y
N
Binding of O2 rupturs dimer pair bods and cause higher oxygen affinity.
F
Y
Oxygenation causes Hb quaternary structure to change. R-state Hb has higher O2 binding affinity than the T state.
T
F
Hb O2 binding/dissociation curve is sigmodial - O2 binding is cooperative
N
Y
Cooperative binding of O2 allows Hb to deliver O2 in response to small changes in pO2
Y
N
2, 3 BPG is a potent allosteric effector that lowers O2 affinity of Hb
Binds tightly to central cavity of deoxyhaemoglobin & stabilizes it.
Y
N
2,3- BPG shifts the O2 binding/dissociation curve to the right – Facilitating unloading of O2 to the tissues
Y
N
H+ protonate His residues at the C-terminal ends of the α & β chains
Y
N
Loss of 2,3, BPG can be reduced by adding substrates such as inosine to storage media. Making it safer for blood transfusion
N
Y
Hb binds extremely to CO which make high affinity of Oxygen without any release as it is in the relaxed form and would lead to CO poisoning.
N
Y
Treatment of CO poisoning: 100% O2 therapy (enables CO to be dissociated from the Hb).
Y
N
