Question | Answer |
What is the main source of galactose for humans? | Milk |
What is galactose used for in the human body? | Galactose is isomerised to glucose to be metabolised. |
A person who is deficient in galactose is said to have? | Galactosaemia |
Fructose is derived from? | Sucrose |
What is involved in the reaction of Fructose to Fructose-1-phosphate (Fructose metabolism)? | Enzyme = fructokinase. 2 ATP are used. F1P is then broken down into G3P to go into glycolytic and CAC pathways. |
What are the problems caused by converting Frtuctose to Fructose-1-phosphate over a long period of time? | It can contribute to obesity as fructose metabolism bypasses phosphofructokinase - the regulatory enzyme in glycolysis. |
What are the two ways by which ATP can be produced? | -Substrate phosphorylation -Oxidative phosphorylation |
Is ATP required to be present in the human diet? | No it is not. ATP is so essential for an organism to function that all organism's can make ATP themselves |
ATP is what type of co-factor? | A nucleotide-based cofactor. |
GTP is used in? | GTP is used in reactions of protein synthesis |
The main function of UTP is? | UTP is used for polysaccharide synthesis |
CTP is used for? | CTP is used for phospholipid synthesis |
Can amino acids be synthesised by humans? | Yes, more than half of the amino acids required can be synthesised by humans. |
What is Transamination? | Transamination is the interconversion of amino and |
What is the main source of galactose for humans? | Milk |
What is galactose used for in the human body? | Galactose is isomerised to glucose to be metabolised. |
A person who is deficient in galactose is said to have? | Galactosaemia |
Fructose is derived from? | Sucrose |
What is involved in the reaction of Fructose to Fructose-1-phosphate (Fructose metabolism)? | Enzyme = fructokinase. 2 ATP are used. F1P is then broken down into G3P to go into glycolytic and CAC pathways. |
What are the problems caused by converting Frtuctose to Fructose-1-phosphate over a long period of time? | It can contribute to obesity as fructose metabolism bypasses phosphofructokinase - the regulatory enzyme in glycolysis. |
What are the two ways by which ATP can be produced? | -Substrate phosphorylation -Oxidative phosphorylation |
Is ATP required to be present in the human diet? | No it is not. ATP is so essential for an organism to function that all organism's can make ATP themselves |
ATP is what type of co-factor? | A nucleotide-based cofactor. |
GTP is used in? | GTP is used in reactions of protein synthesis |
The main function of UTP is? | UTP is used for polysaccharide synthesis |
CTP is used for? | CTP is used for phospholipid synthesis |
Can amino acids be synthesised by humans? | Yes, more than half of the amino acids required can be synthesised by humans. |
What is Transamination? | Transamination is the interconversion of amino and alpha-keto acids by acquiring the amino group from glutamate (Look at course book for equation) |
What undergoes B-oxidation and where does it occur? | Fatty acid-CoA undergoes B-oxidation in the mitochondrial matrix. |
Outline the four main steps of B-oxidation | 1. A dehydrogenase acts upon the a-B C-C bond 2. Hydration of the same bond. 3. 2nd dehydrogenase to yield a B-keto group 4. attack by CoASH: new shorter fatty acid-CoA |
What happens after one cycle of B-oxidation? | After 2 carbons have been broken off the fatty acid in the form of Acetyl-CoA it goes to the CAC. the new shorter FA-CoA re-enters B-oxidation. FADH2 and NADH are reoxidised bt the electron transport chain |
What is the difference between fatty acids with an even number of carbons that undergo B-oxidation and those that have an odd number of carbons? | Even numbered carbon chains are completely oxidised. Odd-carbon fatty acids end up as propionyl-SCoA -> methylmalonyl-CoA (by CO2 fixation) -> succinyl-CoA (which goes to the CAC |
Unsaturated fatty acids need an additional ________ when undergoing B-oxidation to rearrange the ________ ________ | Unsaturated fatty acids need an additional ENZYME when undergoing B-oxidation to rearrange the C=C BOND |
Under what conditions would acetyl-CoA not be oxidised in the CAC? (give reasons) | If there is not enough oxaloacetate. This would only occur when the metabolism of fat outweighs that of carbohydrates |
What are ketone bodies used for? | ketone bodies are used by other body tissues as a METABOLIC FUEL. ketone bodies are readily transported in the blood. |
State the four equations that are involved in the reaction of Acetyl-CoA to ketone Bodies | 1 2acetyl-CoA -> Acetoacetyl CoA Enz =thiolase 2 Acetoacetyl CoA + Acetyl-CoA -> HMG-CoA enz= HMG-CoA synthase 3 HMG-CoA -> Acetoacetate enz = HMG-CoA lyase 4 Acetoacetate ->Acetone/B-hyroxybutyrate Enz = B-hybroxybutyrate dehydrogenase |
Where does the formation of ketone Bodies occur? | In liver mitochondria |
What is another name for vitamin B1? | Thiamine |
What is the dietary requirement for thiamine (vitamin B1)? | 1.0 - 1,5 mg/day. This is increased with fever, heeavy exercise or high carbohydrate intake |
What are good sources of thiamine? | Red meat, whle grains, potatoes, peas, beans, nuts, yeast |
What happens to thiamine when food containing thiamine os cooked and why? | it can be lost as thiamine is water-soluble |
What can contribute to Thaimine deficiency? | It is seen in people who eat rice. Malabsorption, malunitrition, alcohol and diarrhoea can also contribute. Antacids and other medicines that reduce stomach acidity can also destroy it. |
A person who is deficient in Thiamine (vitamin B1) is said to have? | Beriberi. There are two types - wet and dry beriberi. Wet beriberi affects the cardiovascular system. Dry beriberi affects the nervous system |
What are the early symptoms of dry beriberi? | -con stipation - appetite suppression - nausea - mental depression - peripheral neiropathy - fatigue - anorexia - anxiety states - weakness of muscles of extremities |
What are the common characteristics of 'wet beriberi'? | -ataxia - mental confusion - loss of eye coordination - confabulation (the creation of false memories) - disorderede muscle function - accumulation of lactate adn pyruvate in plasma - leads to edema - CARDIAC FAILURE |
A person who has Pellagra is deficient in which vitamin and what are the symptoms? (all 4 symptoms begin with D) | Deficient in Niacin (vitamin B3). Symptoms are - dermatitis - diarrhoea - dementia - death |
Panthothenic Acid is also known as? | Vitamin B5 |
What is the daily requirement for Vitamin B5? | 10-15mg |
Coenzyme A (CoASH) has its reactive thiol compound derived from what? | pantothenate |
What is another name for folate? | Folic acid, or Vitamin B9 |
What is the dietary requirement for Folate? (incl body reserves, daily intake and daily requirement) | Our daily requirement is 100-200ug (this increases to 400+ ug during pregnancy or trauma). Our body reserve is 20mg. Our daily intake is 500-700ug |
What is a source of Folate for humans? | -liver - spinach - citrus - fresh vege's. It is however destroyed by cooking. We also get some folate from our intestinal bacteria. |
What are the main causes of folate deficiency? | poor dietary habits (eg alcoholism) - impaired absorption or metabolism - an increase in the demand, but no increase in the supply ( eg during pregnancy) |
What are the effects of being deficient in folate? | It has an effect on DNA SYNTHESIS as dTMP synthesis is imapired. The result is magaloblastic and macrocytic anaemia |
What is megaloblastic anaemia? | It occurs when there is cell growth without division |
What is macrocytic anaemia? | When there are abnormally large erythrocytes |
What is the RDI of B12? | 3ug/day (50% is absorbed) |
What are common sources of B12? | Liver - kidney - whole milk - eggs - oyster - shrimp - pork - chicken |
Whatis another name for vitamin B12? | "extrinsic factor" cyancobalamin |
A person who is deficient in B12 is said to have? | Pernicious anaemia |
Folic acid deficiencies and Vitamin B12 deficiencies have similar symptoms. True or False? | True. However there are several neurological symptoms that are present in B12 deficiency that do not occur with folate deficiency |
What is Vitamin C also known as? | Ascorbic acid |
A person who has Scurvy if deficient in which vitamin? | Vitamin C (ascorbic acid) |
What are the symptoms of scurvy? | capillary haemorrage - bleeding and peeling gums - impaired wound healing - dissolving away of ground substance - COLLAGEN BREAKDOWN (Vit C involved in post-translational modification of collagens |
What is Vit.C necessary for? | For the maintenance of normal connective tissue (essential for wound healing and the synthesis of connective tissue.) - Synthesis of procollagen - hydroxylation of proline and lysine residues (redox reagent. post-translatoin modification of AA) |
Name dietary sources of Vit C | fruit - uncooked vegetables |
How long doe sit take for scurvy to kick in? | 30-70 days after ascorbic acid-free diet |
How much Vit C does the human body store? | 1.5g (normal) to 4g (fully saturated) |
What is the daily requirement for Vit C? | 45mg |