Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
150 Cards in this Set
- Front
- Back
|
What are the three important disaccharides in human biochemistry ?
|
"1. Maltose
|
|
|
What is maltose a break-down product of ?
|
Starch
|
|
|
Where is lactose found ?
|
In milk
|
|
|
What 2 monomers is lactose composed of ?
|
Galactose + Glucose
|
|
|
What type of sugars is sucrose with regard to chemical reactions ?
|
A non-reducing sugar
|
|
|
What is a homopolysaccharide ?
|
A polysacchiride with a single monomer species
|
|
|
What are the two types of glucose polymer in starch ?
|
Amylose & Amylopectin
|
|
|
What is the difference between Amylose and Amylopectin
|
"- Amylose is unbranched
|
|
|
What are the two types of bonds in Amylopectin and where do they occur ?
|
"Glycosidic α1→4 bonds join glucose in the chains
|
|
|
in what form do animals store glucose ?
|
Glycogen
|
|
|
Give 3 reasons why glucose should be stored in polymers ?
|
"1. compactness
|
|
|
What are glycoproteins ?
|
Proteins that have carbohydrates covalently attached.
|
|
|
What change, if any, is there to solubility of a protein if a carbohydrate is attached ?
|
It increases solubility
|
|
|
Where are glycosaminoglycans found ?
|
In mucus + synorial fluid
|
|
|
What are proteoglycans ?
|
When there is more carbohydrate the protein in a molecule.
|
|
|
what are mucopolysacchiridoses
|
a group of genetic disorders caused by the absence or malfunction of enzymes that are required for the breakdown of glycosaminoglycans.
|
|
|
in which 3 places in the body is carbohydrates digested ?
|
"1. mouth
|
|
|
what are the three main products of digestion of carbohydrates ?
|
"1. glucose
|
|
|
how is glucose absorbed ?
|
by a pump indirectly powered by ATP
|
|
|
how is fructose absorbed ?
|
it binds to a channel protein and then moves down the gradient
|
|
|
what is the use of cellulose and hemicellulose ?
|
"↑ faecal bulk
|
|
|
what are polymers broken down by ?
|
gut bacteria ???? ( not enzymes ???)
|
|
|
what causes lactose intolerance ?
|
a loss of lactase
|
|
|
what is the fate of absorbed glucose ?
|
"- diffuses through epithelium cells to portal blood and then the liver
|
|
|
what does a high Vmax signify ?
|
Efficient enzyme
|
|
|
what does low Km mean ?
|
high affinity substrates
|
|
|
if blood glucose is high, what does the liver do with it ?
|
the liver grabs the glucose
|
|
|
what does the glucokinase do ?
|
phosphoroylates glucose quickly so it can't leave the liver.
|
|
|
where is hexokinase found ?
|
in other tissues (not liver)
|
|
|
what is the purpose of hexokinase ?
|
In has low Km, so has high affinity for glucose. This means that even a loc [Glc] tissues can 'grab' glucose efficiently.
|
|
|
what are the 3 gates of glucose ?
|
"1. CO2 + H2O + ATP
|
|
|
what happens in the liver if the blood concentration of glucose falls ?
|
Glycogen →Glucose in blood
|
|
|
what happens in skeletal muscle if there is no glucose-6-phosphate ?
|
glycolosis leads to lactic acid.
|
|
|
how is glucogen synthesised ?
|
glycogenin binds to uracil-diphosphate-glucose. Then the glucose chains are extended. The chains are broken-off and re-attached via α1-6 bonds to give branch points
|
|
|
what happens in the degradation of glycogen ?
|
The glucose-1-phosphate molecules are released, 3 glucose residues are moved to the nearest non-reducing chainn end and the glucose that was attracting the branch is released.
|
|
|
what is Von Gierke's disease ?
|
liver glucose-6-phosphate deficiency
|
|
|
what is McArdle's disease ?
|
skeletal muscles phosphorylase deficiency
|
|
|
what is gluconeogenisis ?
|
a metabolic pathway that results in the generation of glucose from glycogen
|
|
|
why is gluconeogenesis not a reversible process ?
|
glycolosis cannot be reversed as there are steps with a large -ve ΔG. To overcome this, glyconeogenisis bypasses these reactions with enzymes that catalyse irreversible reactions.
|
|
|
what is the end point of gluconeogenesis ?
|
G-6-P
|
|
|
where does the final step to make free glucose take place ?
|
lumen of ER
|
|
|
what does the pentose phosphate pathway produce ?
|
NADPH
|
|
|
what are pentoses used as ?
|
Precursors of ATP, RNA, and DNA
|
|
|
what is NAD+ used for ?
|
in metabolism of dietry sugars
|
|
|
what is NADP+ used for ?
|
converts simple precursors into things like fatty acids
|
|
|
what does being drunk do to gluconeogenesis and why ?
|
in reduces gluconeogenesis as the NAD+ that would be used in gluconeogenesis is used to breakdown alchohol instead.
|
|
|
what is a oligosaccharide ?
|
a polymer with typically 2-10 monomers
|
|
|
what phosphororylates glucose into glucose-6-phosphate in the liver ?
|
glycokinase
|
|
|
what catalises the phosphorylation of glucose in tissues other than the liver ?
|
hexokinase
|
|
|
what does the citric acid cylce occur ?
|
mitochondrial matix
|
|
|
What are the three important disaccharides in human biochemistry ?
|
"1. Maltose
|
|
|
What is maltose a break-down product of ?
|
Starch
|
|
|
Where is lactose found ?
|
In milk
|
|
|
What 2 monomers is lactose composed of ?
|
Galactose + Glucose
|
|
|
What type of sugars is sucrose with regard to chemical reactions ?
|
A non-reducing sugar
|
|
|
What is a homopolysaccharide ?
|
A polysacchiride with a single monomer species
|
|
|
What are the two types of glucose polymer in starch ?
|
Amylose & Amylopectin
|
|
|
What is the difference between Amylose and Amylopectin
|
"- Amylose is unbranched
|
|
|
What are the two types of bonds in Amylopectin and where do they occur ?
|
"Glycosidic α1→4 bonds join glucose in the chains
|
|
|
in what form do animals store glucose ?
|
Glycogen
|
|
|
Give 3 reasons why glucose should be stored in polymers ?
|
"1. compactness
|
|
|
What are glycoproteins ?
|
Proteins that have carbohydrates covalently attached.
|
|
|
What change, if any, is there to solubility of a protein if a carbohydrate is attached ?
|
It increases solubility
|
|
|
Where are glycosaminoglycans found ?
|
In mucus + synorial fluid
|
|
|
What are proteoglycans ?
|
When there is more carbohydrate the protein in a molecule.
|
|
|
what are mucopolysacchiridoses
|
a group of genetic disorders caused by the absence or malfunction of enzymes that are required for the breakdown of glycosaminoglycans.
|
|
|
in which 3 places in the body is carbohydrates digested ?
|
"1. mouth
|
|
|
what are the three main products of digestion of carbohydrates ?
|
"1. glucose
|
|
|
how is glucose absorbed ?
|
by a pump indirectly powered by ATP
|
|
|
how is fructose absorbed ?
|
it binds to a channel protein and then moves down the gradient
|
|
|
what is the use of cellulose and hemicellulose ?
|
"↑ faecal bulk
|
|
|
what are polymers broken down by ?
|
gut bacteria ???? ( not enzymes ???)
|
|
|
what causes lactose intolerance ?
|
a loss of lactase
|
|
|
what is the fate of absorbed glucose ?
|
"- diffuses through epithelium cells to portal blood and then the liver
|
|
|
what does a high Vmax signify ?
|
Efficient enzyme
|
|
|
what does low Km mean ?
|
high affinity substrates
|
|
|
if blood glucose is high, what does the liver do with it ?
|
the liver grabs the glucose
|
|
|
what does the glucokinase do ?
|
phosphoroylates glucose quickly so it can't leave the liver.
|
|
|
where is hexokinase found ?
|
in other tissues (not liver)
|
|
|
what is the purpose of hexokinase ?
|
In has low Km, so has high affinity for glucose. This means that even a loc [Glc] tissues can 'grab' glucose efficiently.
|
|
|
what are the 3 gates of glucose ?
|
"1. CO2 + H2O + ATP
|
|
|
what happens in the liver if the blood concentration of glucose falls ?
|
Glycogen →Glucose in blood
|
|
|
what happens in skeletal muscle if there is no glucose-6-phosphate ?
|
glycolosis leads to lactic acid.
|
|
|
how is glucogen synthesised ?
|
glycogenin binds to uracil-diphosphate-glucose. Then the glucose chains are extended. The chains are broken-off and re-attached via α1-6 bonds to give branch points
|
|
|
what happens in the degradation of glycogen ?
|
The glucose-1-phosphate molecules are released, 3 glucose residues are moved to the nearest non-reducing chainn end and the glucose that was attracting the branch is released.
|
|
|
what is Von Gierke's disease ?
|
liver glucose-6-phosphate deficiency
|
|
|
what is McArdle's disease ?
|
skeletal muscles phosphorylase deficiency
|
|
|
what is gluconeogenisis ?
|
a metabolic pathway that results in the generation of glucose from glycogen
|
|
|
why is gluconeogenesis not a reversible process ?
|
glycolosis cannot be reversed as there are steps with a large -ve ΔG. To overcome this, glyconeogenisis bypasses these reactions with enzymes that catalyse irreversible reactions.
|
|
|
what is the end point of gluconeogenesis ?
|
G-6-P
|
|
|
where does the final step to make free glucose take place ?
|
lumen of ER
|
|
|
what does the pentose phosphate pathway produce ?
|
NADPH
|
|
|
what are pentoses used as ?
|
Precursors of ATP, RNA, and DNA
|
|
|
what is NAD+ used for ?
|
in metabolism of dietry sugars
|
|
|
what is NADP+ used for ?
|
converts simple precursors into things like fatty acids
|
|
|
what does being drunk do to gluconeogenesis and why ?
|
in reduces gluconeogenesis as the NAD+ that would be used in gluconeogenesis is used to breakdown alchohol instead.
|
|
|
what is a oligosaccharide ?
|
a polymer with typically 2-10 monomers
|
|
|
what phosphororylates glucose into glucose-6-phosphate in the liver ?
|
glycokinase
|
|
|
what catalises the phosphorylation of glucose in tissues other than the liver ?
|
hexokinase
|
|
|
what does the citric acid cylce occur ?
|
mitochondrial matix
|
|
|
What are the three important disaccharides in human biochemistry ?
|
1. Maltose
2. Lactose 3. Sucrose |
|
|
What is maltose a break-down product of ?
|
Starch
|
|
|
Where is lactose found ?
|
In milk
|
|
|
What 2 monomers is lactose composed of ?
|
Galactose + Glucose
|
|
|
What type of sugars is sucrose with regard to chemical reactions ?
|
A non-reducing sugar
|
|
|
What is a homopolysaccharide ?
|
A polysacchiride with a single monomer species
|
|
|
What are the two types of glucose polymer in starch ?
|
Amylose & Amylopectin
|
|
|
What is the difference between Amylose and Amylopectin
|
- Amylose is unbranched
- Amylopectin is branched |
|
|
What are the two types of bonds in Amylopectin and where do they occur ?
|
Glycosidic α1→4 bonds join glucose in the chains
Glycosidic α1→6 bonds join the branches to the chains |
|
|
in what form do animals store glucose ?
|
Glycogen
|
|
|
Give 3 reasons why glucose should be stored in polymers ?
|
1. compactness
2. several non-reducing ends, therefore can be built up and broken down easily. 3. the don't contriburte to the asmotic balance. |
|
|
What are glycoproteins ?
|
Proteins that have carbohydrates covalently attached.
|
|
|
What change, if any, is there to solubility of a protein if a carbohydrate is attached ?
|
It increases solubility
|
|
|
Where are glycosaminoglycans found ?
|
In mucus + synorial fluid
|
|
|
What are proteoglycans ?
|
When there is more carbohydrate the protein in a molecule.
|
|
|
what are mucopolysacchiridoses
|
a group of genetic disorders caused by the absence or malfunction of enzymes that are required for the breakdown of glycosaminoglycans.
|
|
|
in which 3 places in the body is carbohydrates digested ?
|
1. mouth
2. duodenum 3. jejunum |
|
|
what are the three main products of digestion of carbohydrates ?
|
1. glucose
2. galactose 3. fructose |
|
|
how is glucose absorbed ?
|
by a pump indirectly powered by ATP
|
|
|
how is fructose absorbed ?
|
it binds to a channel protein and then moves down the gradient
|
|
|
what is the use of cellulose and hemicellulose ?
|
↑ faecal bulk
↓ Transit time |
|
|
what are polymers broken down by ?
|
gut bacteria ???? ( not enzymes ???)
|
|
|
what causes lactose intolerance ?
|
a loss of lactase
|
|
|
what is the fate of absorbed glucose ?
|
- diffuses through epithelium cells to portal blood and then the liver
- phosphorylated into glucose 6-phosphate by hepatocytes - this traps glucose in the cells |
|
|
what does a high Vmax signify ?
|
Efficient enzyme
|
|
|
what does low Km mean ?
|
high affinity substrates
|
|
|
if blood glucose is high, what does the liver do with it ?
|
the liver grabs the glucose
|
|
|
what does the glucokinase do ?
|
phosphoroylates glucose quickly so it can't leave the liver.
|
|
|
where is hexokinase found ?
|
in other tissues (not liver)
|
|
|
what is the purpose of hexokinase ?
|
In has low Km, so has high affinity for glucose. This means that even a loc [Glc] tissues can 'grab' glucose efficiently.
|
|
|
what are the 3 gates of glucose ?
|
1. CO2 + H2O + ATP
2. pentoses + NADPH 3. Glycogen (stored) |
|
|
what happens in the liver if the blood concentration of glucose falls ?
|
Glycogen →Glucose in blood
|
|
|
what happens in skeletal muscle if there is no glucose-6-phosphate ?
|
glycolosis leads to lactic acid.
|
|
|
how is glucogen synthesised ?
|
glycogenin binds to uracil-diphosphate-glucose. Then the glucose chains are extended. The chains are broken-off and re-attached via α1-6 bonds to give branch points
|
|
|
what happens in the degradation of glycogen ?
|
The glucose-1-phosphate molecules are released, 3 glucose residues are moved to the nearest non-reducing chainn end and the glucose that was attracting the branch is released.
|
|
|
what is Von Gierke's disease ?
|
liver glucose-6-phosphate deficiency
|
|
|
what is McArdle's disease ?
|
skeletal muscles phosphorylase deficiency
|
|
|
what is gluconeogenisis ?
|
a metabolic pathway that results in the generation of glucose from glycogen
|
|
|
why is gluconeogenesis not a reversible process ?
|
glycolosis cannot be reversed as there are steps with a large -ve ΔG. To overcome this, glyconeogenisis bypasses these reactions with enzymes that catalyse irreversible reactions.
|
|
|
what is the end point of gluconeogenesis ?
|
G-6-P
|
|
|
where does the final step to make free glucose take place ?
|
lumen of ER
|
|
|
what does the pentose phosphate pathway produce ?
|
NADPH
|
|
|
what are pentoses used as ?
|
Precursors of ATP, RNA, and DNA
|
|
|
what is NAD+ used for ?
|
in metabolism of dietry sugars
|
|
|
what is NADP+ used for ?
|
converts simple precursors into things like fatty acids
|
|
|
what does being drunk do to gluconeogenesis and why ?
|
in reduces gluconeogenesis as the NAD+ that would be used in gluconeogenesis is used to breakdown alchohol instead.
|
|
|
what is a oligosaccharide ?
|
a polymer with typically 2-10 monomers
|
|
|
what phosphororylates glucose into glucose-6-phosphate in the liver ?
|
glycokinase
|
|
|
what catalises the phosphorylation of glucose in tissues other than the liver ?
|
hexokinase
|
|
|
what does the citric acid cylce occur ?
|
mitochondrial matix
|
