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chemistry 4. 100 spurningar

Terms in this set (84)

How is the presence of cyclic form of glucose expressed?
by a change of monosaccharide solubility
it reacts with Fehling's reagent only at higher temperature
by a change of optical activity
it does not form O-glycosidic bonds
it reacts with Fehling's reagent only at higher temperature
How is the presence of reducing saccharide proven?
by Fehling's reagent
by Tollens' reagent
C. by the nitro-chromic reaction
D. by the reaction with iodine solution
by Fehling's reagent
by Tollens' reagent
The product of the esterification of glucose is:
only glucose-1-phosphate
only glucose-6-phosphate
according to reaction conditions glucose-1,6-biphosphate
phosphoester bond on any of glucose carbon atoms
according to reaction conditions glucose-1,6-biphosphate
L-glucose:
has -OH group bound to the last chiral carbon atom on the left side
is physiologically important for human body
it occurs in urine of diabetic patients
is the left-handed (according to the polarized light) glucose form
has -OH group bound to the last chiral carbon atom on the left side
α-D-fructose-6-phosphate:
is product of the esterification of fructose by phosphane
is product of the reaction of the hydroxyl group of sixth fructose carbon atom with phosphoric acid
cannot be produced, because there is hemiacetal hydroxyl bound to the sixth carbon atom
is product of the esterification of primary -OH group of sixth carbon atom by H3PO4
is product of the reaction of the hydroxyl group of sixth fructose carbon atom with phosphoric acid
is product of the esterification of primary -OH group of sixth carbon atom by H3PO4
Glycosidic bond:
is bond between hemiacetal hydroxyl and -OH group of alcohol
can be formed between hemiacetal hydroxide of one monosaccharide and hemiacetal or primary hydroxyl of other monosaccharide
is a covalent bond. When it is formed the water molecule is released.
is coordination bond, so called donor-acceptor bond
is bond between hemiacetal hydroxyl and -OH group of alcohol
can be formed between hemiacetal hydroxide of one monosaccharide and hemiacetal or primary hydroxyl of other monosaccharide
is a covalent bond. When it is formed the water molecule is released.
Propyl-β-D-glucopyranoside:
is product of the reaction of propanol with β-D-glucopyranose
is the product of the reaction of glucose's hemiacetal hydroxyl in β position and -OH group of propanol
is product of the neutralization of propanol with gluconic acid
propanol cannot react with glucose because there is no hemiacetal hydroxyl in its molecule
is product of the reaction of propanol with β-D-glucopyranose
is the product of the reaction of glucose's hemiacetal hydroxyl in β position and -OH group of propanol
We can say about saccharose:
it is so called beet sugar, and it is the sweetest sugar
there is a glycosidic bond formed in its molecule, that is the product of glucose hemiacetal hydroxyl bonding to primary hydroxyl of the fructose's second carbon atom
there is a glycoside bond formed in its molecule, that is the product of glucose's hemiacetal hydroxyl bonding to hemiacetal hydroxyl of the fructose's second carbon atom
the formule of saccharose's glycosidic bond is α1→ β2
there is a glycoside bond formed in its molecule, that is the product of glucose's hemiacetal hydroxyl bonding to hemiacetal hydroxyl of the fructose's second carbon atom
the formule of saccharose's glycosidic bond is α1→ β2
Saccharose:
contains α-D-glucopyranose and β- L-fructofuranose
is a non-reducing disaccharide, because there is no hemiacetal hydroxyl group in its molecules
is reducing disaccharide, because glycosidic bond is formed between the hemiacetal hydroxyl of glucose and the hemiacetal hydroxyl of fructose
even after its hydrolysis does not give a positive reaction with Fehling's reagent
contains α-D-glucopyranose and β- L-fructofuranose
is a non-reducing disaccharide, because there is no hemiacetal hydroxyl group in its molecules
is reducing disaccharide, because glycosidic bond is formed between the hemiacetal hydroxyl of glucose and the hemiacetal hydroxyl of fructose
We can say about ribose:
it is part of the DNA
it is ketopentose
it is found in ATP
it is an intermediate product of glycolysis
it is found in ATP
Milk sugar:
is reducing saccharide
is galactose
is aldohexose
is lactose
is reducing saccharide
is lactose
Which of these substances does have reducing properties?
starch hydrolysate
lactose
maltose
saccharose
starch hydrolysate
lactose
Saccharose is non-reducing disaccharide because:
glycosidic bond is formed between two hemiacetal hydroxyls
there is no free hemiacetal hydroxyl in the molecule
it does not react with Fehling's reagent
it can not form esters
glycosidic bond is formed between two hemiacetal hydroxyls
there is no free hemiacetal hydroxyl in the molecule
In the reaction of glucose with Fehling's reagent:
the glucose is reduced
the cupric cation (II) is reduced to cuprous cation (I)
the red precipitate of Cu2O is formed
the copper oxidizes
the cupric cation (II) is reduced to cuprous cation (I)
the red precipitate of Cu2O is formed
What is the proof of the presence of glucose by Fehling's reagent based on?
the oxidation of glucose
the oxidation of cupric cation (II)
the reduction of cupric cation (II)
the reduction of hemiacetal hydroxyl
the oxidation of glucose
the reduction of cupric cation (II)
Dihydroxyacetone:
is the simplest ketotrioze
oxidizes to glyceric acid
is formed by glycolysis in the human body
is formed by the oxidation of the secondary carbon atom of glycerol
is the simplest ketotrioze
is formed by glycolysis in the human body
is formed by the oxidation of the secondary carbon atom of glycerol
Maltose:
is glucopyranosyl-glucopyranose
consists of two molecules of α-D-glucopyranose bound by α (1 → 4) bond
is a malt sugar and is formed by starch degradation by maltase
consists of galactopyranose and glucopyranose
is glucopyranosyl-glucopyranose
consists of two molecules of α-D-glucopyranose bound by α (1 → 4) bond
is a malt sugar and is formed by starch degradation by maltase
We can say about lactose:
there is free hemiacetal hydroxyl in its molecule, therefore it is reducing disaccharide
it can be of plant or animal origin
the glycosidic bond β (1 → 4) causes its non-reducing effects
it is split into glucose and galactose by the action of maltase
there is free hemiacetal hydroxyl in its molecule, therefore it is reducing disaccharide
Starch:
is a polysaccharide of plant origin
consists of amylose and amylopectin
contains glycoside bonds α (1 → 4) and β (1 → 4)
contains glycoside bonds α (1 → 4) and α (1 → 6)
is a polysaccharide of plant origin
consists of amylose and amylopectin
contains glycoside bonds α (1 → 4) and α (1 → 6)
Starch, cellulose and glycogen:
differ only in their occurence in nature
do not differ in the composition
differ in the type of glycosidic bond
contain glycosidic bonds α (1 → 4) and α (1 → 6)
do not differ in the composition
differ in the type of glycosidic bond
Starch and glycogen:
are composed of α-D-glucofuranose
contain a glycoside bonds α (1 → 4) and α (1 → 6)
differ in occurrence in nature, starch is the plant polysaccharide and glycogen is of animal origin
differ in water solubility
contain a glycoside bonds α (1 → 4) and α (1 → 6)
differ in occurrence in nature, starch is the plant polysaccharide and glycogen is of animal origin
differ in water solubility
Maltose:
arises from starch by the action of amylase in human body
is formed by the oxidation of mannitol
is split into carbon dioxide, water and energy by maltase
is a reducing disaccharide
arises from starch by the action of amylase in human body
is a reducing disaccharide
Cellulose unlike starch:
is water-soluble
contains glycoside bonds β (1 → 4)
is indigestible to humans, because amylase cleaves only α-glycoside bond
may be proven by iodine solution
contains glycoside bonds β (1 → 4)
is indigestible to humans, because amylase cleaves only α-glycoside bond
We can say about polysaccharides:
glycogen unlike starch and cellulose may be proven by Fehling's reagent
polysaccharides do not have a reducing effects
polysaccharides do not have a sweet taste
glycogen is the storage material in animal body (including human)
polysaccharides do not have a sweet taste
glycogen is the storage material in animal body (including human)
How is glucose formed from disaccharides and polysaccharides?
by the reduction
by the hydrolysis in an acidic medium
by the hydrolysis in the presence of amylase or disaccharidases
it takes place in the stomach by the action of trypsin
by the hydrolysis in an acidic medium
by the hydrolysis in the presence of amylase or disaccharidases
We can say about cellulose:
it is a linear polysaccharide
it forms a colloidal solution in water
it is the most common polysaccharide in the biosphere
it is used in the manufacture of viscose rayon
it is a linear polysaccharide
it is the most common polysaccharide in the biosphere
it is used in the manufacture of viscose rayon
Lipids are:
esters of long chained fatty acids and tertiary alcohol
esters of long chained fatty acids and tribasic alcohol
ethers of long chained fatty acids
ethers of long chained fatty acids and monohydric alcohols with long carbon chain
esters of long chained fatty acids and tribasic alcohol
Lipids are divided into several groups:
according to the origin (plant, animal and synthetic.
according to the alcohol content (acylglycerols and waxes)
according to the composition (simple and phospholipids)
according to the carboxylic acid content (fats and oils)
according to the alcohol content (acylglycerols and waxes)
according to the carboxylic acid content (fats and oils)
What is the importance of lipids in the human body?
they form cell membranes
they create an environment in which non-polar substances, such as vitamins or drugs are dissolved
they are involved in protein synthesis
they are broken down by the action of lipase to form glycerol and fatty acids
they form cell membranes
they create an environment in which non-polar substances, such as vitamins or drugs are dissolved
they are broken down by the action of lipase to form glycerol and fatty acids
Which of following options can be considered to be the unsaturated fatty acid?
linoleic acid
arachic acid
butyric acid
oleic acid
linoleic acid
oleic acid
Which of following options can be considered to be the non-essential fatty acids?
arachidonic acid
aspartic acid
stearic acid
palmitic acid
stearic acid
palmitic acid
Which of following options does contain two or more double bonds in the molecule?
oleic acid
linolenic acid
arachidonic acid
elaidic acid
linolenic acid
arachidonic acid
We can say about lipids:
they are hydrophobic
they are insoluble in cold water but they dissolve in warm water
they need not to be supplied in the diet, because our body can produce them
they are insoluble in water, they can form only colloids or micelles
they are hydrophobic
they are insoluble in water, they can form only colloids or micelles
Which of following options can be considered to be fat?
all lipids of plant origin
lipids that contain a higher percentage of saturated fatty acids
all acylglycerols
mostly lipids of animal origin
lipids that contain a higher percentage of saturated fatty acids
mostly lipids of animal origin
Melting point of lipids:
depends only on the esterified carboxylic acid chain length
depends only on the number of unsaturated bonds in the molecule
depends on the esterified carboxylic acid chain length and the number of unsaturated bonds in the molecule
decreases with shortening of carboxylic acid chain, and with increasing number of unsaturated bonds in the molecule of lipid
depends on the esterified carboxylic acid chain length and the number of unsaturated bonds in the molecule
decreases with shortening of carboxylic acid chain, and with increasing number of unsaturated bonds in the molecule of lipid
Fatty acids are:
water-insoluble carboxylic acids
carboxylic acids, that contain at least sixteen carbon atoms and that have an even number of carbon atoms
unbranched-chain carboxylic acids with minimum of sixteen carbon atoms in their molecules
aromatic carboxylic acids
carboxylic acids, that contain at least sixteen carbon atoms and that have an even number of carbon atoms
unbranched-chain carboxylic acids with minimum of sixteen carbon atoms in their molecules
Essential fatty acids:
are produced by the saturated carboxylic acids dehydrogenation in the human body, so their intake in the diet is not needed
have the aromatic ring or heterocycle in the molecules
have two or more double bonds in their molecules
are important in the metabolism of saturated fatty acids and cholesterol
have two or more double bonds in their molecules
are important in the metabolism of saturated fatty acids and cholesterol
The product of the complete hydrogenation of C19H31COOH is:
oleic acid
linoleic acid
arachidic acid
saturated hydrocarbon
arachidic acid
The product of the reaction of C17H29COOH +2H2 is:
linoleic acid
oleic acid
octadecenoic acid
saturated fatty acid
oleic acid
octadecenoic acid
We can say about lipids:
unsaturated fatty acids in lipid molecules are cis-isomers
trans-isomers of fatty acids are produced by partial hardening of lipids
cool-pressed oils are not suitable for fritting
lipids with high percentage of unsaturated fatty acids are thermostable
unsaturated fatty acids in lipid molecules are cis-isomers
trans-isomers of fatty acids are produced by partial hardening of lipids
cool-pressed oils are not suitable for fritting
Acylglycerols:
can be divided into mono-, di- and tri-acylglycerols
are simple, if there are only saturated fatty acids in their molecules
are combined, if the glycerol is esterified by various fatty acids
contain long-chain monobasic alcohol and long-chain carboxylic acid in the molecule
can be divided into mono-, di- and tri-acylglycerols
are combined, if the glycerol is esterified by various fatty acids
What chemical bond is present in the molecule of simple lipid?
carboxy phosphoesteric bond
esteric bond
O-glycosidic bond
peptide bond
esteric bond
Triacylglycerol:
contains three carboxylic acids bound to the tertiary alcohol, in its molecules
contains carboxylic acids bound together by carboxyl-ester bonds
contains also the phosphoesteric bond
is 1,2,3-propanetriol
contains carboxylic acids bound together by carboxyl-ester bonds
2-stearylglycerol:
is monoglycerol
is composed of stearyl alcohol and glycerol
is glycerol with two esterified carbon atoms
is glycerol with esterified -OH group on the secondary carbon atom
is monoglycerol
is glycerol with esterified -OH group on the secondary carbon atom
We can say about acylglycerol molecule:
there is one, two or three esterified hydroxyl groups there
there are only primary hydroxyl groups esterified
it may contain identical or different long-chained acyls of carboxylic acids
it contains only saturated acyls of fatty acid
there is one, two or three esterified hydroxyl groups there
it may contain identical or different long-chained acyls of carboxylic acids
Simple lipids:
there is glycerol and the alcohol component in their molecules
there is only alcohol component together with long-chained carboxylic acids in their molecules
are, for example, waxes
are, for example, acylcholesterols
there is only alcohol component together with long-chained carboxylic acids in their molecules
are, for example, waxes
are, for example, acylcholesterols
Lipids rancidification (ageing):
is the oxidation of unsaturated bonds
is the oxidation of double bonds of carbon chains resulting in the formation of simple aldehydes and ketones
due to the yellow colour and the smell of new-formed aldehydes and ketones is called yellowing
is not caused by microorganisms in warm and moist environment
is the oxidation of unsaturated bonds
is the oxidation of double bonds of carbon chains resulting in the formation of simple aldehydes and ketones
due to the yellow colour and the smell of new-formed aldehydes and ketones is called yellowing
Lipids hardening:
is catalytic dehydrogenation of oils
is radical substitution
is stepwise reaction
destroys the biological value of plant oils
destroys the biological value of plant oils
Effects of soap as a laundry detergent are based:
on the presence of polar and non-polar molecule parts of sodium palmitate
on the orientation of hydrophobic part of the molecule of the soap into the non-polar impurity structure
on the presence of hydrophilic part of the soap molecule in the surface of micelle
on the fact that the soap precipitates in the hard water
on the presence of polar and non-polar molecule parts of sodium palmitate
on the orientation of hydrophobic part of the molecule of the soap into the non-polar impurity structure
on the presence of hydrophilic part of the soap molecule in the surface of micelle
Complete hydrogenation of linoleic acid forms:
palmitic acid
oleic acid
stearic acid
linolenic acid
stearic acid
The product of the hydrolysis of phospholipids is not:
the phosphoric acid
choline
glycerol
cetyl alcohol
cetyl alcohol
What reaction is the soap product of?
triglyceride hydrolysis in the presence of NaCl
lipid hydrolysis in the presence of NaOH
lipid hydrolysis in the presence of alkaline hydroxide and hydrolase (enzyme)
the reaction of palmitic acid and sodium hydroxide
lipid hydrolysis in the presence of NaOH
the reaction of palmitic acid and sodium hydroxide
Waxes:
are simple lipids
are esters of monohydric alcohols and long chained fatty acids
may contain cetyl alcohol or ceryl alcohol
are only of animal origin
are simple lipids
are esters of monohydric alcohols and long chained fatty acids
may contain cetyl alcohol or ceryl alcohol
Complex lipids:
contain only glycerol esterified with phosphoric acid in the molecule
are for example, phospholipids, that may include choline, serine or ethanolamine in their molecules
are for example, esters of glycerol and phosphoric acid
contain for example galactose or the protein part in their molecules
are for example, phospholipids, that may include choline, serine or ethanolamine in their molecules
contain for example galactose or the protein part in their molecules
We can say about phospholipids:
they contain glycerol esterified by phosphoric acid and choline
they contain only ethanolamine or serine besides glycerol and fatty acids
they consist of glycerol, fatty acids, phosphoric acid
they also contain ethanolamine, choline and serine besides glycerol and the fatty acid
they consist of glycerol, fatty acids, phosphoric acid
they also contain ethanolamine, choline and serine besides glycerol and the fatty acid
Polar part of the phospholipid contains:
H3PO4
ethanolamine, choline and serine
glycerol
anion of an acid
H3PO4
ethanolamine, choline and serine
The non-polar part of the phospholipid contains:
the carbon chain of fatty acid
choline
ethanediol
ethanolamine
the carbon chain of fatty acid
Lipoproteins:
also contain the protein residue besides the alcohol and acid component in the molecule
in the blood plasma are for example involved in cholesterol transport
are found in cell membranes
also contain glucose or galactose in the molecule
also contain the protein residue besides the alcohol and acid component in the molecule
in the blood plasma are for example involved in cholesterol transport
are found in cell membranes
Which of following chemical compounds is/are important for the lipids metabolism?
lipase, which breaks down the lipid ester bonds
gastric acid and pepsin, which breaks down fatty acids
bile acids that emulsify lipids
β-carotene and vitamin C
lipase, which breaks down the lipid ester bonds
bile acids that emulsify lipids
We can say about cholesterol:
it is derived from cyclopentanoperhydrophenanthrene
it can be esterified by long chained carboxylic acid
it does not occur in the human body, it must be supplied in the diet
it occurs as free and esterified (form) in the organism
it is derived from cyclopentanoperhydrophenanthrene
it can be esterified by long chained carboxylic acid
it occurs as free and esterified (form) in the organism
We can say about cholesterol:
it is a part of cell membranes
it is the precursor for insulin and glucagon
it gives rise to bile acids
it is a component of bilirubin and biliverdine
it is a part of cell membranes
it gives rise to bile acids
The cholesterol in the body is precursor for:
sex hormones
bile pigments
vitamin A
bile acids
sex hormones
bile acids
Bile acids:
have shorter side chain than cholesterol
act as enzyme in digestion of fats
are products of cholesterol reduction
contain porphin in the molecule
have shorter side chain than cholesterol
Phytol belongs to:
A. monoterpenes
B. diterpenes
C. triterpenes
D. tetraterpenes
diterpenes
What can be esterified in the molecule of cholesterol:
only hemiacetal hydroxyl
carboxyl group (by glycerol)
hydroxyl group on the third carbon atom
nothing can be esterified there
hydroxyl group on the third carbon atom
We can say about sterols:
phytosterol is of animal origin
ergosterol is found in the yeast
by UV irradiation of ergosterol vitamin B12 is produced
by UV irradiation of ergosterol ergocalciferol, vitamin D2 is produced
ergosterol is found in the yeast
by UV irradiation of ergosterol ergocalciferol, vitamin D2 is produced
Bile acids:
are formed in the liver from cholesterol
are products of the degradation of hemoglobin
are found in adipose tissues, where they are formed from cholesterol
are formed in the small intestine
are formed in the liver from cholesterol
What processes are bile acids important for?
the formation of steroid hormones
the absorption of lipids
the emulsification and breakdown of triglycerides
the hydrolysis of water-insoluble proteins
the absorption of lipids
the emulsification and breakdown of triglycerides
Steroid hormones do not include:
adrenal cortical hormones
corticosteroids
insulin and glucagon
cholecalciferol
insulin and glucagon
cholecalciferol
Proteins in the human body:
have structural and kinetic function, for example - hemoglobin
may be replaced by lipids or polysaccharides
have transport, regulatory and defensive function
are an important component of nucleic acids, as neutral components of nucleotides
have structural and kinetic function, for example - hemoglobin
have transport, regulatory and defensive function
Proteins consist of:
α-amino acids only
neutral amino acids such as serine, valine or glycine only
the neutral saccharide component, alkaline base and amino acid
amino acids having only one-COOH group and one-NH2 group in the molecule
α-amino acids only
Essential amino acids:
must be supplied in the diet
have one-NH2 group bound to the β-carbon
are for example phenylalanine, tryptophan and lysine
contain the heterocycle in their molecules
must be supplied in the diet
are for example phenylalanine, tryptophan and lysine
Heterocycle is contained in the molecule of: A. tyrosine
B. tryptophan
C. histidine
D. asparagine
B. tryptophan
C. histidine
We can say about amino acids:
they occur only in the food of animal origin
the organism can produce glucose from them
non-essential amino acids are formed by transamination of oxo acids in the human body
the product of matabolism of amino acids is urea in human body
the organism can produce glucose from them
non-essential amino acids are formed by transamination of oxo acids in the human body
the product of matabolism of amino acids is urea in human body
We can say about tyrosine:
it is a hormone that is produced in the thyroid gland
its precursor may be phenylalanine in the organism
it is a hydroxy derivative of phenylalanine
it does not have an aromatic character
it is a hormone that is produced in the thyroid gland
it does not have an aromatic charac
Which of following amino acids can be considered to be acidic?
glutaric acid
glutamic acid
aspartic acid
ascorbic acid
glutamic acid
aspartic acid
Which of amino acids can be considered to be basic?
lysine, proline, histidine
histamine, arginine, asparagine
lysine, histidine, arginine
amino acid that has more -NH2 groups than -COOH groups in the molecule
lysine, histidine, arginine
amino acid that has more -NH2 groups than -COOH groups in the molecule
Characteristic reactions of amino acids are:
dehydrating reactions
decarboxylation and deamination reactions
redox reactions
condensation and transamination reactions
decarboxylation and deamination reactions
condensation and transamination reactions
Transamination:
is the reaction of preparing non-essential amino acids
takes place in the presence of a derivative of vitamin B6 - transaminase (coenzyme)
is the reduction of oxogroup
is for example, the production of tryptophan
is the reaction of preparing non-essential amino acids
takes place in the presence of a derivative of vitamin B6 - transaminase (coenzyme)
We can say about peptide bond:
it is a stable covalent bond
it has a planar structure
we can prove it by biuret reaction
it is very stable and only cleaves during denaturation
it is a stable covalent bond
it has a planar structure
we can prove it by biuret reaction
pI value:
is dissociation constant of the amino acid
for essential acids is equal to 7
is pH of the medium in which the amino acid is in the form of amfion (zwitterion)
is characteristic for each amino acid
is pH of the medium in which the amino acid is in the form of amfion (zwitterion)
is characteristic for each amino acid
The primary structure of proteins:
indicates the biological value of protein and determines higher protein structures (secondary, tertiary. . . )
is determined by amino acid sequence in the polynucleotide chain
is stabilized by hydrogen bonds between molecules of amino acids
is determined by the order of amino acids bound by peptide bonds
indicates the biological value of protein and determines higher protein structures (secondary, tertiary. . . )
is determined by the order of amino acids bound by peptide bonds
We can say about the geometric arrangement of polypeptides:
it is called α-helix, if hydrogen bonds are formed between the oxygen and hydrogen atoms of peptide bonds in a single polypeptide chain
amino acid residues are bound together by van der Waals forces within the helix
amino acid residues do not participate in the secondary structure, they are arranged into the outer space of helix
it is not destroyed by denaturation
it is called α-helix, if hydrogen bonds are formed between the oxygen and hydrogen atoms of peptide bonds in a single polypeptide chain
amino acid residues do not participate in the secondary structure, they are arranged into the outer space of helix
We can say about proteins:
they are found in the blood of a healthy person
they are found in the urine of healthy person
important ones are only of plant origin
they play an important role as a part of nucleic acids
they are found in the blood of a healthy person
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