Option B. Biochemistry Flashcards

1
Q

What is metabolism?

A

Metabolism is the sum of all chemical reactions taking place in an organism.

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2
Q

What are metabolic pathways?

A

Methabolic pathways are the controlled sequences in which metabolic reactions occur.

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3
Q

What are metabolites?

A

Metabolites are all the compounds that take part in metabolism

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4
Q

What is anabolism?

A

Anabolism is the synthesis of biomolecules. Precursors form larger molecules by and endothermic reaction.

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5
Q

What is catabolism?

A

Catabolism is the break down of molecules to CO₂ and H₂O. Catabolism is an exothermic reaction.

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5
Q

What are condensation reactions?

A

The loss of H₂O and the formation of a convalent bond between monomers with 2 functional groups.

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6
Q

What are hydrolysis reactions?

A

The addition of H₂O breaks covalent bonds. The H₂O will split to -H and -OH and attach seperately to the product molecules.

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7
Q

What is photosynthesis?

A

Photosynthesis is an an anabolic series of redox reactions that allow green plants to synthesis energy-rich molecules

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8
Q

What is cell respiration?

A

Cell respiration is a metabolic series of redox reactions that breaks down energy-rich molecules to release energy.

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9
Q

What are proteins?

A

Macromolecules made up of chains of 2-amino acids.

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10
Q

What two functional groups are present in 2-amino acids?

A
  • Carboxyl group
  • Amino group
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11
Q

What are zwitterions

A

Zwitterions are dipolar ions, they have 2 different charges.

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12
Q

What is the isoelectric point?

A

The isoelectric point is the specific pH at which an amino acid is a zwitterion.

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13
Q

What happens to an amino acid in an acidic environment?

A

They behave as a base and will have a positive charge

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14
Q

What happens to an amino acid in a basic environment?

A

It will behave as an acid and will be negatively charged.

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15
Q

What is the primary structure of proteins?

A

The sequence of amino acids

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16
Q

What is the secondry structure of proteins?

A

Describes the way that a polypeptide folds itself due to intermolecular hydrogen bonding.
* a-helix: the chain is spiraled like a colied spring
* B-pleated sheet: folds itself as a flat sheet.

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17
Q

What is the tertiary structure of proteins?

A

Describes folding och the chain by interactions between distant amino acids to give the protein its 3-d shape.
* Hydrogen bonds
* London forces
* Ionic attractions
* Disulphide bridges

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18
Q

What is the quartenary structure of proteins?

A

Several polypeptides interacting to give a complex structure.

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19
Q

What are fibrous proteins?

A

Fibres such as keratin. They are structural components that are elongated muscles with mainly secondary structure. They are insoluble in water.

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20
Q

What are globular proteins?

A

Tools that operate at a molecular level, for example hemoglobin. They are compact spherical molecules with mainly tertiary structure. They are water soluble

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21
Q

What does chromatography do?

A

Seperates molecules based on their affinity for the mobile and the stationary phase. The molecules will move with the mobile speed at different speeds and therefore seperate.

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22
Q

What uses do proteins have in the body?

A
  • Enzymes
  • Structural proteins
  • Hormones
  • Antibodies
  • Transport
  • Energy
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22
Q

What does electrophoresis do?

A

Seperates amino acids based on charge. The amino acids will move differently based on how far away their isoelectric point is from the pH of the buffer. They either move towards a positive charge or a negative charge.

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23
Q

What are enzymes?

A

Globular proteins that can catalyse biological reactions.

24
Q

How are enzymes specific?

A

Their specificity is determined by their tertiary and quartenary structure.

25
Q

How does substrate concentration affect rate of reaction?

A

At lower concentration the rate will be proportional to the substrate concentration. At higher concentration the rate will reach a maximum, this is when all the enzyme molecules are used.

26
Q

How does temperature affect enzymes?

A

All enzymes have an optimal temperature where they work the most efficiently. If the temperature exceeds the optimal temperature to much, the enzyme will denature and no longer work.

27
Q

How does pH affect enzymes?

A

All enzymes have an optimal pH where they work the most efficiently. If the pH exceeds the optimal pH to much, the enzyme will denature and no longer work.

28
Q

What are triesters?

A

Triglycerids that are formed by the reaction between propane-1,2,3-triol and 3 fatty acids.

29
Q

What is hydrolysis of fats?

A

Hydrolysis is the opposite of formation of triesters. They are broken down to glycerol and fatty acids, who in turn are broken down to carbon dioxide, water and energy

30
Q

What ate saturated fatty acids?

A

Fatty acids who only have single C-C bonds.

31
Q

What are unsaturated fatty acids?

A

Fatty acids who have atleast one double C=C bond. Poly unsaturated fatty acids have more than one double C=C bond.

32
Q

What are essential fatty acids?

A

Fatty acids that humans need but can not synthesise.
Ex:
* 6 linoleic acid (omega-6)
* 3 linoleic acid (omega-3)

33
Q

What is iodine number?

A

Iodine number is the measurement of the number of double bonds in fat. The higher the iodine number the more the unsaturated the fat is.

34
Q

What is rancidity?

A

Rancidity is when we percieve that food has gone bad. This is noticed by bad smells, weird textures and apperance.

35
Q

What is hydrolytic rancidity?

A

Rancidity of triesters due to hydrolysis. This produces smelly fatty acids. It is catalysed by heat and lipase, but can be inhibited by refrigeration.

36
Q

What is oxidative rancidity?

A

Rancidity of fats due to oxidation. This is oxygen being added to double bonded C atoms. It is a free-radical mechanism, catalysed by light in the presnece of enzymes, but it can be slowedby the addition of antioxidants.

37
Q

What are phospholipids composed of?

A
  • Glycerol
  • Phosphate group
  • Nitrogen containing alcohol (polar)
  • Two fatty acids (non polar)
38
Q

What roles do lipids have in the body?

A
  • Energy storage
  • Insulation and protection of organs
  • Steroid hormones
  • Structural component of cell membranes
39
Q

What positive health effects can lipids have?

A

Omega-3 can reduce the risk of heart disease.
Polyunstaturated fats may lower LDL cholesterol levels.

40
Q

What negative health effects can lipids have?

A

Saturated/transfats can increase cholestrol
Contribute to obesity

41
Q

What does cholesterol do?

A

Cholsterol is mainly used for synthesising hormones (ex sex hormones) and some vitamins (ex vitamin D). It is transported around via lipoproteins

42
Q

What is low density lipoproteins (LDL)?

A

A lipoprotein consisting of 20-25% of protein. Transports cholesterol through the blood stream to repair and build tissue. Tends to accumulate in arteries since it contains lots of lipids. This can lead to heart disease.

43
Q

What is high density lipproteins (HDL)?

A

A lipoprotein consisting of 40-45% of protein. They can pick up cholesterol from arteries and transport it back to the liver.

44
Q

What are the female sex hormones?

A
  • Progesterone
  • Oestrogen
45
Q

What are the male sex hormones?

A
  • Testosterone
  • Androsterone
46
Q

What is testosterone used for?

A

It is used to gain weight and train muscles. For this reason it is banned in most sports.

47
Q

What is the general formula for carbohydrates?

A

Cₓ(H₂O)ᵧ

48
Q

What is the general formula of monosaccharides?

A

CH₂O

49
Q

What is pentose?

A

Pentose are monosaccharides with 5 carbon atoms. Examples are ribose and deoxyribose

50
Q

What is hexose?

A

Hexose are monosaccharides with 6 carbon atoms. Examples are glucose and fructose

51
Q

What structures does glucose have?

A
  • Straight chain glucose
  • α-glucose
52
Q

What structures does fructose have?

A
  • Straight chain fructose
  • α-fructose
53
Q

What is sucrose?

A

α-D-glucose + β-D-fructose

54
Q

What is maltose?

A

α-D-glucose + α-D-glucose

55
Q

What is lactose?

A

β-D-galactose + β-D-glucose

56
Q

What forms do starch have?

A

Amylose - a straight chain of α-D-glucose with α-1.4 bonds.
Amylopectin - a branched chain of α-D-glucose with α-1.4 and α-1.6 bonds.

57
Q

What is cellulose?

A

A polymer of β-D-glucose with 1.4 bonds. It provides the structure to the cell wall of plant cells.

58
Q

What is glycogen?

A

A polymer of α-D-glucose with 1.4 and 1.6 bonds. It is what we store carbohydrates as in the body.

59
Q

What is the use of carbohydrates?

A
  • Energy source
  • Energy reserves
  • Precursors for biological molecules
  • Dietary fibres which can prevent some conditions:
60
Q

What conditions can dietary fibres prevent?

A
  • IBS
  • Obesity
  • Crohn’s disease
  • Haemorrhoids
  • Diabetis mellitus (type 2)