XI Chap 9 Biomolecules Flashcards
An elemental analysis on plant tissue, animal tissue or microbial paste would result in what elements?
carbone, hydrogen, oxygen
The elemental analysis on a plant/animal tissue and a piece of earth’s crust would obtain similar elements. T or F?
True
Relative abundance of carbon, hydrogen and oxygen with respect to other elements is higher in ____________
living organisms or Earth’s crust?
living organisms
Describe how to conduct chemical analysis
take any living tissue
grind it in trichloroacetic acid –> thick slurry
strain using cheesecloth/cotton -> examine the filtrate for organic compounds
More technically accurate name for filtrate and retentate in chemical analysis of living tissue?
Filtrate: Acid-soluble pool
Retentate: acid-insoluble fraction
All the carbon compounds that we get from living tissues can be called ___________
biomolecules
Living organisms have both organic and inorganic elements and compounds in them. T or F?
True
How does one obtain the inorganic elements/compounds from living tissue?
Destructive experiment
Dry it, remaining material is dry weight. Burn tissue fully, all C compounds are oxidised to gaseous forms, remaining contains inorganic elements
What is ‘ash’
remains after drying and burning a tissue
Inorganic substances like sulphate and phosphate are also seen in the acid-soluble fraction. T or F?
True
Elemental analysis gives ____________ while analysis for compounds gives _________
elemental composition of living tissues (hydrogen, oxygen, etc.)
idea of organic and inorganic constituents
Amino acids are ______ compounds containing an amino group and a acidic group as ________ on the same ______
organic, substituents, carbon
Amino acids are on the alpha carbon, hence they are called ________
alpha amino acids
Amino acids are substituted _______
methanes
In amino acids, there are 4 _________ groups occupying ____ valency positions.
substituent, 4
What are the 4 substituent groups in amino acids?
Hydrogen
Carboxyl group
Amino group
Variable - R group
Based on the nature of _____ group there are many amino acids.
R
Only ______ (how many) types of amino acids occur in proteins
20
3 examples of R group in proteinaceous amino acids?
hydrogen H (glycine),
methyl group CH3 (alanine),
hydroxy methyl CH2-OH (serine)
Chemical and physical properties of amino acids are essentially of:
amino, carboxyl and R functional groups
Based on number of amino and carboxyl groups, there are _____ (what types of amino acids?)
acidic (glutamic)
basic (lysine, arginine)
neutral (valine)
What are some aromatic amino acids?
tyrosine,
phenylalanine,
tryptophan
Why is it that in solutions of different pH the structure of amino acids changes?
due to the ionizable nature of NH2 and COOH groups
% weight of the Hydrogen in Earth’s crust vs human body
0.14% (earth’s crust) vs 0.5% (human)
% weight of the Carbon in Earth’s crust vs human body
0.03% (earth’s crust) vs 18.5% (human)
% weight of the Oxygen in Earth’s crust vs human body
46.6% (earth’s crust) vs 65% (human)
% weight of the Nitrogen in Earth’s crust vs human body
very little (earth’s crust) vs 3.3 (human)
% weight of the Sulphur in Earth’s crust vs human body
0.03 (earth’s crust) vs 0.3 (human)
% weight of the Sodium in Earth’s crust vs human body
2.8 (earth’s crust) vs 0.2 (human)
% weight of the Calcium in Earth’s crust vs human body
3.6 (earth’s crust) vs 1.5 (human)
% weight of the Magnesium in Earth’s crust vs human body
2.1 (earth’s crust) vs 0.1 (human)
% weight of the Silicon in Earth’s crust vs human body
27.7 (earth’s crust) vs negligible (human)
What are “other” inorganic compounds found in living tissues (table 9.2)?
NaCl, CaCO3, PO4 3-, SO4 2-
Lipids are generally water insoluble or soluble?
Insoluble
A fatty acid has a _______ group attached to a _____ group
carboxyl group, R group
R group in simple fatty acid could be a _______ or _____ or ________
methyl (CH3) or ethyl (C2H5) or higher number of -CH2 groups (1 to 19 carbons)
Palmitic acid has _____ carbons including carboxyl carbon
16 carbons
Arachidonic acid has _____ carbons including carboxyl carbon
20 carbons
Fatty acids could be saturated or unsaturated. What do the bonds look like in each?
Saturated - without double bond
Unsaturated - with one or more C=C double bonds
Glycerol is a simple lipid. T or F?
True
Many lipids have both glycerol and fatty acids. T or F?
True
Glycerol is tri… ?
trihydroxy propane
In some lipids, fatty acids are found _______ with glycerol. What are the 3 types?
esterified,
mono, di and triglycerides
Mono-, di- and triglycerides are also called ____ and _____ based on melting points.
fats and oils
Fats have have a lower melting point than oils. T or F?
False
Some lipids have phosphorous and a _________ in them. They’re called phospholipids.
phosphorylated organic/nitrogenous compound
Phospholipids are found in _____ membrane.
cell
Lecithin is a __________
amino acid - phospholipid - carbohydrate - nucleoside
phospholipid
_________ tissues have lipids with more complex structures.
Neural
Nitrogen bases have ____ rings
heterocyclic
What are the nitrogen bases?
Adenine, Guanine, Thymine, Uracil and Cytosine
When nitrogen bases are attached to a sugar they are called ___________
nucleosides
When phosphate group is found esterified to sugar, in addition to nitrogen base, it is called _______
nucleotide
Name nucleosides and tides?
Nucleosides: Adenosine, guanosine, cytidine, thymidine, uridine
Nucleotides: Adenylic acid, guanylic acid, cytidylic acid, thymidylic acid, uridylic acid
DNA and RNA consist of nucleotides only. T or F?
True
If one were to make a list of biomolecules it would consist of 1000s of organic compounds. T or F?
True
Biomolecules are also known as ___________. Why?
metabolites
because all metabolic reactions result in transformation of biomolecules. they’re required for metabolic reactions and the results of these reactions.
In what tissues are all of these compounds present?
Alkaloids, flavonoids, rubber, essential oils, antibiotics, coloured pigments, scents, gums and spices
What are these compounds aka?
plant tissues;
secondary metabolites
In what tissues are all of these compounds present?
H, C, O, N, S, Na, Ca, Mg and Si
What are these compounds aka?
animal tissues;
primary metabolites
Primary vs. secondary metabolites?
Primary - animals, identifiable functions
secondary - plants, not all in-body functions are known but useful to human welfare & ecologically important
Carotenoids and anthocyanins are examples of?
pigments (secondary metabolites)
Morphine, Nicotine, trychnine, caffeine and Codeine are examples of?
alkaloids (secondary metabolites)
Monoterpenes, Diterpenes are examples of?
terpenoids (secondary metabolites)
Lemon grass oil is an example of?
essential oil (secondary metabolites)
Abrin and Ricin are examples of?
Toxins (secondary metabolites)
Concanavalin A is example of?
Lectin (secondary metabolites)
Vinblastin, curcumin are examples of?
drugs (secondary metabolites)
Rubber, gums, cellulose are examples of?
Polymeric substances (secondary metabolites)
What is one feature common to all compounds found in the acid-soluble pool?
molecular weights ranging from 18 to 800 daltons (Da)
Acid insoluble fraction has how many types of organic compounds? What are they?
4,
proteins, nucleic acids, polysaccharides and lipids
All acid soluble pool compounds weigh less than 800 Da whereas all acid insoluble pool compounds weigh in range of 10,000 Da and above (hence later called macromolecules). T or F?
False, first half is true, but not all acid insoluble pool compounds are heavy. Lipids do not exceed 800 Da.
Most molecules in the acid insoluble pool have molecular weights in the range of __________
10,000 Da and above
What are the 2 types of biomolecules (based on weight)
micromolecules - <1000 Da
macromolecules - >1000 Da (aka those found in acid insoluble fraction)
Biomacromolecules (and this excludes lipids) are polymeric substances. T or F?
True
Why do lipids come under acid insoluble fraction if they are so small?
cell membrane and other membranes are broken into pieces when tissue is ground. Forms vesicles that are not water soluble. Therefore they get separated along with acid insoluble pool.
Acid soluble pool roughly represents _______ composition
Cytoplasm
___________ and ___________ from the cytoplasm become the acid insoluble fraction
Macromolecules, organelles
__________ is the most abundant chemical in living organisms
Water
Proteins are polypeptides, ________ chains of amino acids linked by ____________
linear, peptide bonds
Each protein is a polymer of ___________
amino acids
A protein is a homo or heterpolymer?
Heteropolymer
What are essential amino acids? What is their source?
Cannot be made by our body. We get them from our diet/food.
Functions of proteins?
- transport nutrients across cell membrane
- fight infections
- hormones
- enzymes
- receptors
- structural proteins
_________ is the most abundant protein in animal world;
__________ is the most abundant protein in the biosphere
Collagen - animal
RuBisCo - biosphere
What is the function of collagen (protein)?
Intercellular ground substance
What is the function of trypsin (protein)?
enzyme
Acid insoluble pellet has carbohydrates. T or F?
True, polysaccharides
What is the function of insulin (protein)?
hormone
What is the function of antibody (protein)?
fights infectious agents
What is the function of receptor (protein)?
Sensory reception (smell, taste, hormone, etc.)
What is the function of GLUT-4 (protein)?
Enables glucose transport into cell
Polysaccharides are long chains of ________. They are threads containing different _______ as building blocks.
sugars; monosaccharides
Cellulose has how many types of monosaccharides?
1 - glucose
Cellulose is a homopolymer. T or F?
True, made of glucose only
_______ is a variant of cellulose, present as a store house of energy in plants whereas ______ variant is present in animals
starch, glycogen
______ is a polymer of fructose
Inulin
In glycogen (polysaccharide chain) , right end is called _________, left end is called _________
reducing, non-reducing
Polysaccharide chains have branches. T or F?
True
Starch forms _________ structures that can hold ______
helical secondary structures, can hold I2 molecules
Starch is ____ in color, while cellulose isn’t. What explains this?
blue.
Starch can hold I2, cellulose can’t (complex helixes absent)
Plant walls are made of ________
cellulose
Paper made from plant pulp and cotton fibre is __________
cellulosic
Complex polysaccharides found in nature have what as building blocks?
Amino-sugars and chemically modified sugars (glucosamine, N-acetyl galactosamine, etc.)
What are glucosamine and N-acetyl galactosamine?
amino-sugars / chemically modified sugars in complex polysaccharides
___________ of arthropods have complex polysaccharides called _____
Exoskeleton, chitin
Complex polysaccharides are mostly homopolymers (remember, the simple polysaccharide cellulose is a homopolymer). T or F?
True
Nucleic acids are poly…..
polynucleotides
Polysaccharides, polypeptides and polynucleotides comprise the ______ of any living tissue/cell
true macromolecular fraction
Building block for nucleic acids is _________
nucleotide
3 distinct compounds of nucleotide?
heterocyclic compound (nitrogen base) monosaccharide (5-carbon sugar) phosphoric acid / phosphate
Sugar found in polynucleotides is either ribose (a _______ pentose) or ___-deoxyribose
monosaccharide, 2’
In inorganic chemistry, structure referes to _______
molecular formulae
Organic chemists always write a ________ view of molecules
2-D
Physicists conjure up ________ views of molecular structures
3-D
Biologists describe protein structure at how many levels? what are they?
4 levels:
- primary - sequence / positional info
- secondary - helix and other forms
- tertiary - hollow woolen ball
- quaternary - architecture of polypeptides / subunits wrt each other
In primary structure, protein is imagined as a ______, leftmost of which is ____ and rightmost is ____
line, first amino acid, last amino acid
First amino acid in primary structure is called _____, last is called _____
N-terminal
C-terminal
Protein thread exists throughout as an extended rigid rod. T or F?
False
Some portions of protein thread is folded in ___________ and some are folded into other forms
right handed helix
Tertiary view gives us a ____-dimensional view of a protein
3-D
_________ structure is absolute necessary for the many biological activities of proteins
Tertiary
Some proteins are an assembly of more than one polypeptide or subunits. T or F?
True (quaternary structure)
Linear string of spheres,
spheres arranged one upon each other in form of a cube or plate
^ what are these?
architecture of a protein (quarternary structure)
What is the quarternary structure of adult human haemoglobin?
4 subunits, 2 identical to each other.
2 subunits of alpha, two of beta
Peptide bonds of amino acids are formed when _____ group of one AA reacts with _____ group of the next AA with the elimination of ______. This process is called _____.
carboxyl (COOH) group
amino (NH2) group
water moeity
dehydration
In a polysaccharide, monosaccharides are linked by a peptide bond. T or F?
False, glycosidic
Peptides and glycosidic bonds are formed by _______ process
dehydration
Glycosidic bond is formed between _______ atoms of two adjacent _______
2 carbon atoms, 2 adjacent monosaccharides
In a nucleic acid, a _______ links the ______ of one sugar of one nucleotide to the _______ of the sugar of the succeeding nucleotide.
What is this bond called?
phosphate moeity, 3’C, 5’C
ester bond
Why is it said that polypeptides have phosphodiester linkage?
2 ester bonds on either sides / chains => phosphodiester
The Watson-Crick model (double helix) is one of many secondary structures exhibited by nucleic acids. T or F?
True
The strand of DNA turns how many degrees in each step? in a full turn?
36, 360
One full turn of a helical strand includes how many base pairs?
10
Pitch of DNA is ____, rise per bp is _____
34 Å, 3.4 Å
DNA that exhibits the Watson-Crick model features is called ___-DNA
B-DNA
There are more than ______ forms of DNA named after English alphabets with unique structural features
a dozen
Biomolecules are present in certain concentrations measured as ______ or _____
mols/cell of mols/litre
One of the greatest discoveries ever made wrt biomolecules is ______
all biomolecules have a turn over => constantly being changed into other biomolecules and made from other biomolecules
Turn over of biomolecules occurs through _______
chemical reactions aka metabolism
removal of CO2 from amino acids making an amino acid into an amine is an example of?
metabolic reaction
hydrolysis of a glycosidic bond in disaccharide is an example of?
metabolic reaction
Most metabolic reactions occur in isolation. T or F?
False, series of linked reactions (hence metabolic pathways)
Metabolic pathways can be _____ or _______ and always _____ each other
linear or circular, always criss-cross each other
Metabolic pathways are compared to what real-life phenomenon?
Traffic
Metabolic pathways have a definite ____And ____
rate and direction
Metabolite flow is called __________
dynamic state of body constituents
Every metabolic reaction in living systems is catalysed, even physical processes. T or F?
True
Catalysts which hasten rate of metabolic conversations are also ________ and named ______
proteins, named enzymes
Anabolic vs. catabolic pathways?
Anabolic - simple to complex, consumes energy
Catabolic - complex to simple, releases energy, trapped and stored as chemical bonds
Anabolic pathways are aka _______
biosynthetic pathways
Anabolic or catabolic?
Amino acids => proteins
Glucose => lactic acid
Acetic acid => cholesterol
Amino acids => proteins - anabolic
Glucose => lactic acid - catabolic
Acetic acid => cholesterol - anabolic
When glucose is degraded to lactic acid, it is called _____ and occurs in how many steps?
glycolysis, 10 steps
Stored bond energy is utilised for biosynthetic, osmotic and mechanical work in the body as and when required. T or F?
True
Most important form of energy currency is _______
bond energy in a chemical called adenosine triphosphate (ATP)
Blood concentration of glucose in healthy individual is __________
4.2 - 6.1 mmol/L
Concentration of hormones in normal healthy person is measured in ________
nanograms / mL
Most important fact of biological systems is ____________
all living organisms exist in a steady-state characterised by concentrations of each of the biomolecules
Biomolecules in our bodies are in a state of __________ flux
metabolic
The steady state (or “living state”) in human beings is an equilibrium state where you will find biomolecules in specific ranges of quantities. T or F?
False, steady state = non-equilibrium… system is continuously working (metabolism)
Living process is a constant effort to prevent falling into equilibrium. T or F?
True
How is living state achieved?
energy input from metabolism
All enzymes are proteins. T or F?
False, ALMOST all enzymes, some nucleic acids can be enzymes too (ribozymes)
One can depict enzyme by _____ diagram
line
An enzyme, like any protein, has primary, secondary and tertiary structures. T or F?
True
In a tertiary structure, the backbone of a protein folds upon itself, criss-crosses itself, and hence many _______ are made. These are called “__________”.
crevices / pockets.
“active sites”
_______ fits into an active site of an enzyme
substrate
Enzymes, through their ________, catalyse reactions at a high rate.
active sites
What is one major difference b/w enzyme catalysts and inorganic catalysts?
Enzymes get damaged at high temperatures (above 40° C), while inorganic catalysts work efficiently at high temps and high pressures.
Enzymes isolated from _________ organisms are stable at high temps (80°-90° C)
thermophilic organisms (live in hot vents and sulphur springs)
Chemical compounds undergo 2 types of changes:
physical (change in shape, no breaking of bonds) and chemical (breaking and forming of bonds)
Ba(OH)2 + H2SO4 -> BASO4 + 2H2O
is organic or inorganic chemical reaction?
Inorganic
Hydrolisis of starch into glucose…
is organic or inorganic chemical reaction?
Organic
What is the rate of a physical / chemical process?
Amount of product formed per unit time.
r = delta P/ delta t
If direction is specified, rate can also be called ______
velocity
Rates of physical and chemical processes are affected by temperature. T or F?
True
General rule of thumb is that rate increases by ______ for every _____°C increase of temperature.
doubles, 10°C
CO2 + H20 -> H2CO3 (carbonic acid)
What is the rate of uncatalysed reaction? Catalysed?
Uncatalysed - 200 molecules of carbonic acid formed in an hour
Catalysed - 600,000 molecules per second
(10 million times faster)
What is the enzyme associated with converting CO2 and water to carbonic acid? By how much does using an enzyme increase the rate of the reaction?
Carbonic anhydrase, 10 million times
A multistep chemical reaction where each step is catalysed by the same enzyme complex or different enzymes is called a ___________
metabolic pathway
Glucose -> 2 Pyruvic acid is an example of:
physical reaction - metabolic pathway - single-enzyme reaction - single-step reaction
metabolic pathway
Glucose becomes pyruvic acid through how many enzymes?
10
The glucose to pyruvic acid metabolic pathway can yield what end product in human body under anaerobic conditions? aerobic? in yeast?
anaerobic - lactic acid
aerobic - pyruvic acid
yeast - ethanol
Chemical converted to a product in a reaction is called ________
substrate
What does S —> P symbolize?
Chemical conversion of substrate to product (in enzymes, via active sites)
Formation of an ‘ES’ complex is a __________ phenomenon
transient
During the state where S is bound to E active site, a new structure of substrate called ______ is formed
transition state structure
Pathway of S -> P transformation must go through the ________________
transition state structure
In S -> P, there could be many altered structural states between the stable substrate and product. T or F?
True
When there are multiple transition state structures, all intermediate structures are stable. T or F?
False, unstable
Stability is something related to the _____ status of the molecule / structure.
energy
If P is at lower level than S, the reaction is ________.
If S is lower level than P, then reaction is ________.
Exothermic/spontaneous
Endothermic/energy-requiring
Only in endothermic reactions, where P is higher than S, S has to go through a much higher transition state. T or F?
False, in both endothermic and exothermic reactions.
Enzymes ______ the energy barrier making transition of S to P much easier
bring down
Formation of ES complex is short-lived. T or F?
True
What is EP?
intermediate formation of enzyme-product
ES -> EP -> E + P
Describe the catalytic cycle of enzyme reaction:
- substrate binds to active site
- induces the enzyme to alter its shape, fitting more tightly around substrate
- active site is now in close proximity of substrate -> breaks chemical bonds -> EP is formed
- enzyme releases products, ready to bind to another molecule of substrate
What are the 4 factors affecting enzyme activity?
- pH
- temperature
- concentration of substrate
- binding of regulators
Enzymes function in a wide range of temperature and pH. Outside this range it is inactive or destroyed. T or F?
False, narrow range, everything else correct
Temp / pH where enzyme shows its highest activity is called ___________ temp/pH
optimum
Low temperatures _________ the enzyme whereas high temperatures ______ the enzyme because __________
preserve/inactivate,
destroy,
proteins are denatured by heat
With the increase in substrate concentration, __________ of reaction increases at first.
velocity
What is max velocity in enzymatic reaction?
rate of reaction is not increased by any further rise in concentration of substrate because no free enzyme molecules left to bind with additional substrate
Max velocity is reached when substrate molecules are greater than enzyme molecules. T or F?
True
What are inhibitors/inhibition?
when binding of chemical shuts off enzyme activity
What is competitive inhibitor? Example
When inhibitor closely resembles substrate in molecular structure and inhibits enzyme activity.
e.g. inhibition of succinate dehydrogenase by malonate (substrate is succinate)
Competitive inhibition is used in the control of _________ pathogens
bacterial
Enzymes are divided into ____ classes each with ______ subclasses and named accordingly by a ___-digit number
6, 4-13, four-digit
What are the 6 classes of enzymes?
Oxidoreductases/dehydrogenase Transferase Hydrolase Lyase Isomerase Ligase
What are oxidoreductases? aka?
enzymes which catalyse oxidoreduction b/w 2 substrates. aka dehydrogenase
What are transferases?
enzymes which catalyse transfer of a group, G (other than hydrogen) between a pair of substrates
What are hydrolases?
enzymes which catalyse hydrolysis of ester, ether, peptide, glycosidic, C-C, C-halide or P-N bonds
What are lyases?
enzymes which catalyse removal of groups from substrates by mechanisms other than hydrolysis leaving double bonds
What are isomerases?
enzymes which catalyse inter-conversion of optical, geometric or positional isomers
What are ligases?
enzymes catalysing the linking together of 2 compounds e.g. joining of C-O, C-S, C-N, P-O
Match the reactions to the class of enzymes?
- S-G + S’ –> S’-G + S
- X-C-C-Y –> X-Y + C=C
- S reduced + S’ oxidised –> S oxidised + S’ reduced
- Transferase
- Lyase
- Dehydrogenase / oxidoreductase
Enzymes are composed of one or several __________ chains
polypeptide
What are co-factors?
non-protein constituents
often bound to enzyme
make enzyme catalytically active
What is apoenzyme?
Protein portion of the enzyme (when co-factors are present)
3 kinds of cofactors?
prosthetic
co-enzymes
metal ions
Prosthetic groups?
co-factors of enzymes,
organic compounds,
tightly bound to apoenzyme
Co-enzyme?
co-factor of enzyme,
organic compound,
association with apoenzyme is only transient during the catalysis
Essential elements of many co-enzymes are ________
vitamins
Coenzyme nicotinamide adenine dinucleotide contains __________ vitamin
niacin
Metal ions as co-factors?
form coordination bonds with side chains at the active site
and coordination bonds with substrate
Catalytic activity is lost when co-factor is removed. T or F?
True
Match the following to the right group of co-factors and name the GROUP of the co-factor.
1. Peroxidase and catalase - breakdown of hydrogen peroxide to water and O2
2. NAD and NADP
3. proteolytic enzyme carboxypeptidase
Options: Niacin - Zinc - Haem
- Haem - prosthetic
- Niacin - co-enzyme
- Zinc - metal ion
Although there is bewildering diversity of living organisms, their chemical composition and metabolic reactions appear to be remarkably similar. T or F?
True
There are _____ types of amino acids and ____ types of nucleotides
20, 5
Lipids because of association with _______ separate in the macromolecular fraction
membranes
__________ enzymes exhibit substrate specificity
proteinaceous enzymes
Enzymes increase or lower the activation energy of reactions?
Lower
Carbohydrates (sugars) are chemically defined as ______________ or ______________
polyhydroxy aldehyde, ketones
All sugar molecules have one ______________ group in addition to a ______________ group on other carbon atoms.
carbonyl group (-CO-) hydroxyl group (OH)
Neutral or true fats are ______________ (mono/di/triglycerides) which are formed by esterification of ______________ molecules of fatty acids with one molecule of ______________
triglycerides,
3,
trihydric alcohol, glycerol (glycerine or trihydroxy propane)
Basic amino acids have an additional amino group without forming ______________ thus they are ______________
amides, diamino monocarboxylic acids
Major role of minor elements inside living organisms is to act as ______________
co-factors of enzymes
Spoilage of oil can be detected by which fatty acid?
Erucic acid
Essential amino acid is?
phenylalanine - glycine - aspartic acid - serine
phenylalanine
Water present in human body is ______________
65-70%
Water present in living cell is ______________
70-90%
Proteins in living cell is ______________
10-15%
Carbohydrates and lipids in living cells are ______________ and ______________ respectively
3%
2%
Nucleic acids make up ______________% of living cells
5-7%
Ions make up ______________% of living cell mass
1%
Nicotine, strychnine and caffeine are used as ______________ in plants
defense mechanisms
Which of the following have carbohydrate as prosthetic group?
Glycoprotein - lipoprotein - chromoprotein - nucleoprotein
Glycoprotein
Sucrose is a ______________ (mono / disaccharide)
disaccharide
Glycine is a sulphur containing amino acid. T or F?
False
Which of the following is a non-reducing carbohydrate?
Maltose - sucrose - lactose - ribose 5-phosphate
Sucrose
Macromolecule chitin is a _________-containing polysaccharide
nitrogen
Carbohydrates are commonly found as starch in plant storage organs because they are ______________ and ______________
chemically non-reactive, osmotically inactive
Cellulose is a major component of cell walls of:
pseudomonas - saccharomyces - pythium - xanthomonas
Pythium
Carbohydrates, the most abundant biomolecule on earth, are produced by __________, algae and green plant cells.
Fungi, some bacteria or all bacteria?
some bacteria (that contain chlorophyll)
Galactose is a ______________ (reducing / non-reducing) sugar
reducing
Cellulose, the most important constituent of plant cell wall is made up of:
unbranched chain of glucose molecules linked by β-1, 4 glycosidic bond
Lactose is composed of ___________
glucose + galactose
Which purine base is found in RNA?
thymine - uracil - cytosine - guanine
Guanine (says PURINE!!)
Ramachandran plot is used to confirm the structure of ___________
proteins
Which of the following is least likely to be involved in stabilising the 3-D folding of most proteins?
Ester bonds
In double helical structure of DNA, density of DNA decreases on heating. T or F?
True, as hydrogen bonds breakdown
In double helical structure of DNA, A + T/C + G is not constant. T or F?
False, it is constant for a species, may vary species to species
In double helix of DNA, two DNA strands are coiled around ___________
a common axis
Modern detergents contain enzyme preparations of ___________
alkaliphiles (alkaline protease for removing protein stains)
Feedback inihibition is inhibition of the activity of an enzyme catalysing some early reactions of the series by the ___________
end product of the metabolic pathway
