Topic 2: Molecular Biology

O Trans fatty acids

________ have no kinks because they have been artificially hydrogenated in a factory.

Oxygen

________ is therefore a waste product and diffuses away.

Collision

________: when enzyme and substrate come together.

Triglycerides

________ are fats if solid at room temperature and oils if liquid.

Collagen

like protein made of three polypeptides wound together.

Adrenaline

________ can cause the body to sweat even when cold because it anticipates a period of intense activity.

Methane

________ is liquid over a range of 22˚C whereas water is liquid over a range of 100˚C.

O Glaciation

________ occurred due to reduction of greenhouse effect- fall in methane and carbon dioxide concentrations.

Lactate production

Used to maximize the power of muscle contractions.

Reaction mixture

________ is heated to 72˚C for 80 seconds, during which 1, 000 nucleotides are added per minute.

Sunlight

________ is a mixture of different wavelengths.

amino acids

All ________, however, are soluble enough to dissolve in blood plasma.

RNA polymerase

________ binds to it at the start of a gene and then moves along to separate the two DNA strands.

Hydrogen bonds

Adhesive properties: ________ between water and other polar molecules.

Large subunit

________ makes peptide bonds between amino acids to link them together into a polypeptide.

Collisions

________ occur because of random movements and are successful when the substrate and active site are correctly lined up to each other.

chain reaction

Polymerase ________ (PCR): Use of Taq DNA polymerase to produce multiple copies of a specific DNA sequence.

Enzymes

________ are immobilized by attaching them to other substances or into aggregations to restrict movement.

● Cholesterol

________: Mainly hydrophobic: Insoluble in water.

bundles

Un- branched chains allow them to form ________, connected by hydrogen bonds and created cellulose microfibrils.

Soluble

________ proteins become insoluble and form a precipitate because hydrophobic groups become exposed to water.

Solvent properties

________: Polar nature of water means that it forms shells around other polar molecules.

Fatty Acids

________: Can be mono /polyunsaturated or saturated.

Solubility

________ depends on the R group.

Insulin

________: Signal to cells to absorb glucose.

Proteomes

________: All of the proteins produced by a cell, tissue or organism.

Metabolism

________: Web of all enzymes catalyzed reactions in a cell or organism.

aerobic cell respiration

Energy from triglyceride can be released from ________.

● Glycogen

________: Similar to amylopectin in structure; but has more branching.

Messenger RNA

________ and genetic code: mRNA determines all sequences of polypeptides according to genetic code.

Light energy

________ splits molecules of water to release electrons needed in other stages.

lactic acid

● In humans, glucose is converted into ________.

Starch

________: Made by linking alpha- glucose molecules.

Aerobic respiration

________: Requires oxygen and produces a large yield of ATP from glucose.

Photosynthesis

________ is an anabolic process.

Water

________ has a higher specific heat capacity, latent heat of evaporation and thus a higher boiling point.

bacterial antigens

Binding sites for ________ have a different binding site- specific immunity.

Advantages

________: Easily separated from products of reaction, preventing contamination of products.

glycosidic bond

Link between two monosaccharides is called a(n) ________.

Proteins

________ usually contain sulfur.

Monomers

________=> Macromolecules by condensation reactions.

OH

All- ________ molecules point downwards, hence all molecules have a similar orientation, which results in a curved structure.

Transcription

________: Synthesis of mRNA from the DNA base sequence using RNA polymerase.

variety of substances

Transport in blood plasma: Blood transports a(n) ________.

tensile strength

They are located in the skin, blood vessel walls to prevent tearing and allow for ________.

Phospholipids

________ act as a vesicle, with hydrophobic fatty tails on the insides, facing the fatty molecule.

DNA Helicase

________: Unwinds the double helix and separates the two strands by breaking the hydrogen bonds.

Anaerobic respiration

________: Gives a small yield of ATP from glucose, which is broken down without oxygen.

O Ribosomes

________ move along mRNA and tRNA is removed leaving one space for new tRNA molecules.

Anabolism

________: Synthesis of complex molecules from simpler ones.

2 Molecular Biology 2.1 Molecules to metabolism Molecular biology

● Reductionist approach in coming to conclusions

Synthesis of Urea

● Ammonia + Carbon Dioxide => Ammonium Carbonate => urea + water ● Synthesized in the liver due to excess amino acids (deamination)

Vitalism

● Origin of all life comes due to a "vital principle", which is different to life being composed purely of chemical + physical forces

● Saturated fatty acids

Carbon atoms form an unbranched chain of about 14-20 atoms, no double bonds

● Amino Acids

Contain Amine group; Carboxyl group; Hydrogen atom; and R variable group

Metabolism

● Web of all enzymes catalyzed reactions in a cell or organism

● Anabolism

Synthesis of complex molecules from simpler ones

● Catabolism

Breakdown of complex molecules into simpler ones including the hydrolysis of macromolecules into monomers

2.2 Water Hydrogen bonding in water

● Water molecules are polar and hydrogen bonds form between them

● Adhesive properties

Hydrogen bonds between water and other polar molecules

● Solvent properties

Polar nature of water means that it forms shells around other polar molecules

Substances that are insoluble are hydrophobic

uncharged and nonpolar particles, like lipids

● Water vs. Methane

Both small molecules linked by single covalent bonds and have similar masses

● Sweat as a coolant

Heat needed for the evaporation of water in sweat is taken from the tissues of the skin, reducing their temperature

Transport in blood plasma

Blood transports a variety of substances

● Amino Acids

Both negative and positive charges

● Glucose

Freely soluble because it is polar

● Oxygen

Non-polar molecule

● Fatty molecules

Entire nonpolar and large

● Monosaccharides

Glucose, fructose, galactose and ribose

● Disaccharides

Two monosaccharides linked together

Maltose

glucose + glucose

● Cellulose

Linking beta glucose in a 1-4 structure makes cellulose

● Starch

Made by linking alpha-glucose molecules

This forms two types

amylose and amylopectin

● Glycogen

Similar to amylopectin in structure; but has more branching

Has some 1-6 linkages in addition to 1-4 linkages Lipids

● Triglycerides are formed by condensation from three fatty acids and glycerol

Energy storage

● Lipids are more suitable for long-term energy storage than carbohydrates

Body Mass Index (BMI)

● BMI = Mass (kg)/(Height (m))2

Fatty Acids

● Can be mono/polyunsaturated or saturated

Health risks

● Main concern is CHD (Coronary Heart Disorder)

2.4 Proteins Amino acids and polypeptides

● Amino acids are linked together by condensation to form polypeptides

● Polypeptide

20 or more amino acids

Diversity of amino acids

● 20 different amino acids in polypeptides

Proteins and polypeptides

● Protein may consist of two single polypeptides or more than one polypeptide linked together

● Collagen

3 polypeptides

● Hemoglobin

4 polypeptides

Denaturation of protein

● Heat/pH extremes (causes)

● Insulin

Signal to cells to absorb glucose

Binding sites for bacterial antigens have a different binding site

specific immunity

● Collagen

Rope-like protein made of three polypeptides wound together

● Rhodopsin

Pigments of rhodopsin, membrane proteins of rod cells in the retina are light sensitive molecules surrounded by an opsin polypeptide

● Spider silk

Polypeptide forms parallel arrays very resistant to breaking

Proteomes

● All of the proteins produced by a cell, tissue or organism

● Enzyme substrate specificity

one enzyme can facilitate one particular substrate only

● Collision

when enzyme and substrate come together

Factors affecting enzyme activity ● Temperature

Higher kinetic energy leads to greater rate of collision and an increased chance of a successful collision as the energy could exceed the activation energy needed for the reaction to proceed

● pH

Enzymes have an optimum pH for functionality

When the H+ ion concentration is higher/lower than the optimum, enzyme activity is hindered and the structure of the enzyme is altered

another example of denaturation

● Advantages

o Easily separated from products of reaction, preventing contamination of products