Biological Molecules Flashcards

Question

What affects enzymes activity? X4

Answer 1

TEMPERATURE: As temp increases so does rate of enzyme controlled reaction. More kinetic energy and vibrations. Increased collisions. Optimum temp changes active sight and enzyme denatures. PH: Opt pH value (mostly pH 7) Enzyme denatured at any ph above or below the opt due to H+ and OH- ions found in acids and alkalis because they mess up ionic and hydrogen bonds in the enzymes structure. ENZYME CONCENTRATION: More enzymes increases the rate of the reaction because there are more things for the substrates to collides with to for E-SC. But when limited substrate, more enzymes will have no effect. SUBSTRATE CONCENTRATION: More substrate molecules increases rate of reaction. More collisions. Only until saturation point though.

Answer 2

Bing to enzymes. Inside active site. Same shape as the substrate to competes with it to get to active site but no reaction takes place. BLOCK. If high concentration of inhibitor, rate of reaction will be much slower. But high substrate concentration increases their chances of binding to enzyme, increasing rate of reaction.

Answer 3

Inhibitor binds outside the enzymes structure. Away from active site. Changes active site shape to substrate no longer binds. Don’t complete with substrate because they are different shape. Increasing substrate concentration won’t make a difference.

Answer 4

Made of nucleotides. DNA and RNA are nucleic acids carrying information. Structure = pentose + nitrogen containing organic base + phosphate group. Ester bonds between phosphate group and pentode sugar. Glycosidic Bon between pentose sugar and base. Condensation reactions occur to join pentose sugar to phosphate group and base and water is removed.

Answer 5

DEOXYRIBOSE NUCLEIC ACID: 2 polynucleotide chains (anti parallel) in double helix. HYDROGEN BONDS!!! Complimentary bases = A-T, C-G. Pentose sugar (5 C atoms) = deoxyribose. Phosphate group. 4 types of bases : adenine, guanine, THYMINE, cytosine. RNA = ribose Short polynucleotide chain (only one) Ribose sugar. Phosphate group. 4 types of bases : adenine, URACIL, cytosine, guanine. C-3-G = THREE BONDS BETWEEN A-2-T = TWO BONDS BETWEEN Adenine and guanine are purine due to double ringed structure. Cytosine and thymine are pyrimidines due to single ring. C

Answer 6

Polymers of nucleotides. (Formed by DNA or RNA) Join by condensation reactions between phosphate group and sugar of different nucleotides. PHOSPHODIESTER BONDS!! (Phosphate and 2 ester bonds) Chain of sugars = sugar-phosphate backbone.

Answer 7

DNA copies before cell division. Semi conservative is only half of strands of each new dna molecules or of ogininal dna. Steps: 1. DNA helicase enzyme breaks H bond between bases on two polynucleotides dna strands. UNWINDS and form 2 single strands. 2. Each original strand is a template for a new strand. Complimentary base pairings means the free-floating dna nucleotides are attracted to the exposed bases and match up. 3. Condensation reactions join together the nucleotides catalysed by the enzyme DNA polymerise. H bonds form between bases. 4. Each new dna polymerase molecule contains a new strand and an organically strand (semi conservative).

Answer 8

Theory to test semi conservative replication (in conservative, original DNA strands would have stayed together and new DNA molecules would create new strands). Uses ISOTOPES of NITROGEN!!! - Heavy = 15N Light = 14N 1. Bacteria grown (2x) one light and one heavy. Bacteria reproduces and take up nitrogen for DNA nucleotides. 2. DNA sample taken from each and SPUN in CENTRIFUGE. DNA from heavy nitrogen settles lower than lighter because its heavier. 3. Bacteria from heavy nitrogen taken out and put into light nitrogen. Becateria left for round of dna replication then new dna spun again in centrifuge. 4. If conservative, original heavy will settle at bottom and new, light at top. 5. If semi conservative, new bacterial dna would contain 1 strand of old dna (heavy) and one of new (light). So dna would settle would between them. 6. Dna settles in the middle showing that its a mixture of the heavy and light N. The bacteria dna had replicated semi-conservatively in light N.

Answer 9

Structure: H2O Shared electrons. Due to negative h electrons pulled towards O2 atom then other side of each h atom is left with a positive charge. O2 atom has slight negative charge. Polar molecule - partially neg and partially pos. Function: Metabolite in metabolic reactions like condensation and hydrolysis. It’s a solvent so things can dissolve in it. Help temperature control due to high latent heat of vaporisation and high specific heat capacity. Water molecules are cohesive so stick together and helps transport in plants.

Answer 10

1. Important metabolite - condensation and hydrolysis 2. High latent heat of vapourisation - takes lots of energy to break H bonds and lots of energy to vaporise it. Useful because organisms wont lose water as easily. 3. Can buffer (resist) temp changes - h bonds absorb energy due to high specific heat capacity. Useful as water doesn’t react to large temperature changes. 4. Good solvent - due to polarity. 5. Strong cohesion between water molecules - due to polarity, helps water flow and transporting substances, also means high surface tension when in contact with air.

Answer 11

ADENINE + RIBOSE + PHOSPHATE X3! Energy released from glucose used to make ATP. Nucleotide derivative due to modified form of nucleotide. Once made, ATP diffuses to part of the cell that needs energy. Energy of ATP stored in high energy bonds between phosphate group. Released via hydrolysis. When energy is needed by the cell, ATP is HYDROLYSED into ADP > phsosphate bond broken > energy released (catalyst = ATP hydrolyse. Can be re-synthesised in condensation reaction > hydrolysed by ATP synthesise.

Answer 12

Inorganic ions have an electric charge and NO CARBON. Positive - cation. Negative - anion. In cytoplasm and bodily fluids of organisms. Ions role depends on high or low concentrations. Haemoglobin = protein that carries O2 in RBCs. - made of 4 polypeptide chains with iron ion. - it binds to the O2 which turns FE2+ into FE3+ temporarily until o2 is released.

Answer 13

HYDROGEN IONS: - determines pH - more H+ = lower pH (acidic) - affects enzyme controlled reactions (denaturation) IRON IONS: - component in haemoglobin (in polypeptide chains) - FE2+ + O2 = FE3+ SODIUM IONS: - co-transport of glucose and amino acids - helps them cross membranes PHOSPHATE IONS: - components of DNA and ATP. - production of ATP and phospholipids and nuclei acids. - especially in membranes - when phosphate bonds broken in ATP lots of energy is released. CALCIUM IONS: - required for blood clotting - forms matrix in cellulose in plant cells - transmitting of impulses from neurone to neurone - stimulates muscle contraction - regulate protein channels - enzymes activated by CA2+ POTASSIUM IONS: - constantly pumped into the into cells by active transport in exchange for sodium ions. - important in transport of nerve impulses. MAGNESIUM IONS: - forms chlorophyll - important for light absorption NITRATE IONS: - production of amino acids and proteins from carbs in plants by photosynthesis. CHLORIDE IONS: - moved out of cells lining lungs and digestive system to provide low water potential outside cell causing water to follow so mucus less thick and stiff. - lack of it causes cystic fibrosis.

Answer 14

Eukaryotes: DNA is linear and have HISTONES to form chromosomes. HISTONES order DNA into nucleosomes which the DNA winds around. Some organelles also have DNA like like mitochondria and chloroplasts. Prokaryotes: Small, circular and not associated with proteins. NO CHROMOSOMES. Additional DNA in plasmids.

Answer 15

RRNA - ribosomal (80% of all rna) - involved in formation of ribosomes and important for protein synthesis. MRNA - messenger (3-5% of all rna) - single stranded and forms in nucleus. - uses sone strand of DNA as a template. - communicates genetic code in allele to ribosome during protein synthesis. TRNA - transfer (15% of all rna) - single stranded, clover leaf molecule. - H bonds - carry amino acids through cytoplasm to correct places in growing polypeptide chain.