C5 Chemistry of Life Flashcards

Question

Describe the 3 differences between DNA + RNA.

Answer 1

DNA - deoxyribose sugar - adenine, guanine, cytosine, thymine - double stranded RNA - ribose sugar - adenine, guanine, cytosine, uracil - single stranded

Answer 2

- biological catalyst (lower the activation energy for the body's chemical reactions - they facilitate, speed up + control reactions - not a reactant: are unchanged after reaction and can be used again STRUCTURE - globular proteins - many unique enzymes, each with a specific active site (AS) - AS of an enzyme has a specific complementary shape to a specific substrate (reactant)

Answer 3

INDUCED FIT MODEL - can be either anabolic reactions or catabolic reactions 1. The substrate bonds to the enzyme's active site. 2. AS changes to become more complementary to the substrate, forming the enzyme-substrate complex (ESC) 3. The reaction occurs (anabolic/catabolic), products are released

Answer 4

- Catabolic: polymers to monomers - Anabolic: monomers to polymers

Answer 5

TEMP - each enzyme has an optimum (37°C for humans) - Lower: slower ROR = less KE = less reactions - Higher: enzyme denatures (AS changes shape) - graph will increase to optimum, then rapidly decrease (denaturing) pH - each enzyme has an optimum pH depending on where it functions in the body (e.g. stomach = pH 2) - graph will increase to optimum, then rapidly decrease (denaturing) Substrate - substrate conc increases = ROR increases - limited by enzyme conc - graph will increase then plateau Enzyme - enzyme conc increases = ROR increases - limited by substrate conc - graph will increase then plateau

Answer 6

ASSISTING Cofactors - inorganic molecules that bond with the allosteric site of an enzyme - changes shape of the AS to be more complementary to the substrate Co-enzymes/co-substrates - organic molecules that bond with the AS - help substrate bond faster to enzyme INHIBITING Competitive - molecule bonds to the AS, preventing the substrate from bonding - reaction cannot occur Non-competitive - molecule bonds to the allosteric site, changing the shape of the AS - substrate cannot bond, reaction cannot occur

Answer 7

another site on an enzyme, seperate from the active site, that molecules are able to bond to - can be used for assisting or inhibiting enzyme activity

Answer 8

the controlled release of energy from organic compounds (glucose, usually) in cells to form ATP - glucose + oxygen = carbon dioxide + water + ATP

Answer 9

Adenosine Triphosphate - type of nucleic acid: adenine base, ribose sugar, 3 phosphate groups - is a high energy molecule and an immediate power source for cell processes HOW - ATP releases energy via being hydrolysed (a cycle) - the third phosphate is held by an unstable bond, when it is released, it releases energy - results in ADP (Di) and Pi (the released phosphate) - ADP = low battery, energy used - can then be regenerated by adding Pi to form ATP again - ATP = full battery, energy ready to be released

Answer 10

ANAEROBIC - absence of O2 - partial breakdown of glucose - in the cytosol - small yield of ATP (2) from glycolysis AEROBIC - presence of O2 - complete breakdown of glucose - in the mitochondria - large yield of ATP (30-38) - aerobic is far more efficient - anaerobic is essential when the body is not able to get enough O2 to all cells (e.g. heavy exercise)

Answer 11

GLUCOSE | Glycolysis (cytoplasm) - 2 ATP | PYRUVATE | If O2 not present: Anaerobic CR (cytoplasm) - no more ATP produced - fermentation TOTAL: 2 ATP | If O2 present: Aerobic CR (mitochondria) - 30-34 ATP TOTAL: 30-38 ATP

Answer 12

GLYCOLYSIS - in cytoplasm - starting process of both AN + AE resp Glucose is broken down into: - 2x pyruvate - 2x NADH (a co-enzyme needed for AE resp) - 2x ATP

Answer 13

AE RESP - in mitochondria - when O2 is present Process: - link reaction - Krebs cycle - electron transport chain Pyruvate converted to: - CO2 - H2O - (ideally) 34-36 ATP NET YIELD: 30-38 ATP (glycolysis + AE resp)

Answer 14

AN RESP - in cytoplasm - when O2 is absent (body cannot get to cells fast enough) FERMENTATION Why - body cannot get O2 to cells fast enough, all stored ATP is used up, but energy is needed - AN resp restores NAD+ (needed in glycolysis reaction to convert to NADH) - the fermentation cycle allows glycolysis to continue to produce ATP in a low O2 environment Pyruvate (from glycolysis) converted to: - Animals: lactic acid (lactate) - Bacteria/yeast: ethanol + CO2 Process - is a reversible cycle - once O2 is present, lactic acid/ethanol is converted back to pyruvate - AE then continues as normal TOTAL YIELD: 2 ATP (glycolysis)

Answer 15

- carbon dioxide + water = glucose + oxygen STAGE 1: Light Dependent - Process: photolysis - chlorophyll absorbs photon (light E) from the sun, excites H2O electrons, they become delocalised - chlorophyll takes an electron from H2O molecule, SPLITTING it into H2 (used in Stage 2), O2 (waste), + producing ATP - photon - chlorophyll - ATP + H2 (+ O2 waste) STAGE 2: Light Independent - Process: carbon fixation - H2 + ATP (from S1) + CO2 (from air) react to produce glucose

Answer 16

- waxy cuticle: top + bottom of leaf - upper epidermis: transparent, allowing max light penetration for max Phs rate - palisade mesophyll: contains chloroplasts which contain chlorophyll, the main photosynthetic pigment - vascular bundle: xylem delivers H2O to cells for Phs, phloem transports glucose produced from Phs - spongy mesophyll: spaced out for gas exchange - stomata (pores): controlled by guard cells, facilitate GE (CO2 in, O2 out)

Answer 17

DIRECTLY - production of O2 (e.g. count bubbles produced by water plants) - uptake of CO2 (e.g. enviro pH increase) INDIRECTLY - increase in biomass (total mass of plant)

Answer 18

TEMP - increase in temp = more KE = more frequent collisions = higher rate of Phs - graph has increase, then optimum, then decrease due to denaturing LIGHT INTENSITY - increase in light = more energy to drive reaction = higher Phs rate - graph will increase then plateau when chloroplasts are working at max efficiency CO2 CONC - increase in CO2 = more substrate = higher Phs rate - graph will increase then plateau due to another limiting factor

Answer 19

- complementary reactions within the environment - products of Phs are inputs of CR, vice versa - PHS: CO2 + H2O = C6H12O6 + O2 - CR: O2 + C6H12O6 = H2O + CO2 DIFFERENCES - Phs: anabolic, synthesises/builds glucose - CR: catabolic, breaks down glucose - producers perform both, consumers perform just CR SIMILARITIES - both involve ATP production - Phs: ATP produced via light energy, used to make glucose - CR: ATP produced via breakdown of glucose - both require enzymes to complete the reaction

Answer 20

- used to measure O2/glucose production, CO2/H2O use - demonstrates the relationship between CR + Phs (time of day/light on X axis, glucose/carb production on Y axis) - COMP POINT: when what is produced by Phs = what is used by CR (no excess), Phs rate = CR rate, usually occur at dusk/dawn - ABOVE CP: plant is producing more glucose then it is using - BELOW CP: plant is using more glucose than it is producing TIME OF DAY - rate of Phs is dependent (due to light availability) - highest rate is at midday - rate of CR is not dependent - rate remains relatively stable throughout day - goes up slightly when Phs increases, as needs small amount of ATP to start up

Answer 21

- Role of DNA: contains/carries all genetic information/genes for all cells - A + T (double H bond), G + C (triple H bond) BACKBONE - sugar phosphate backbone formed by the phosphates/sugars of nucleotides bonding to form a polynucleotide (polymer) - function: provide support + protection to N bases DOUBLE HELIX - caused by antiparallel strands (strands run in opposite directions) - causes twisting of strands to form an energy stable structure (the helix) - a fold occurs every 10-15 base pairs REPLICATION Stage 1 - Helicase enzyme moves along helix and unwinds DNA strands - each parent strand is a template for a new complementary daughter strand Stage 2 - DNA polymerase enzyme synthesises both new strands - the strands have complementary bases to parent strands - both stages happen at once - the process is semi-conservative (uses half of already formed material, half is created)

Answer 22

WHY - DNA is too large and unstable to leave the nucleus - protein synthesis allows for singular genes to be transferred outside the nucleus, using mRNA, for a protein to be made TRANSCRIPTION - in nucleus - DNA is unwound at the location of the specific gene - a complementary strand of mRNA is made (U instead of T) - after it is formed, exits nucleus via a nuclear pore TRANSLATION - in cytoplasm - mRNA binds to a ribosome - ribosome translates mRNA one codon at a time - tRNA (transport) with complementary anti-codons (same as og DNA gene, but with U) drops off the specific AA that corresponds to the codon - the AAs bond together to form a PP chain - after entire mRNA strand is translated, the PP chain is formed

Answer 23

3 bases, a set - code for a specific AA - translated together by a ribosome during protein synthesis

Answer 24

messenger RNA - a smaller, more stable nucleic acid used to transfer specific genes outside the nucleus during protein synthesis

Answer 25

transport RNA - a T shaped RNA molecule - has anticodons to the mRNA strand - brings a specific AA for each codon to form the PP chain

Answer 26

- a change in a single nucleotide in the DNA code, leading to a gene mutation WAYS - Substitution: base is replaced with a different one (ATG to ACG) - Inversion: two bases next to each other swap places (ATG to AGT) - Insertion: base is added in - Deletion: base is deleted EFFECTS - Missense mutation: mutation alters a single AA, leading to genetic variation, not always bad - Nonsense mutation: mutation causes a premature stop codon, PP chain is incomplete and dysfunctional, usually bad - Frameshift mutation: insertion/deletion shifts the entire DNA strand, PP chain is dysfunctional, usually very bad - Silent mutation: base changes but still codes for correct AA, no effect (this is possible as the DNA code = degenerate: alternate substances can perform the same function)

C5 Chemistry of Life Flashcards

(50 cards)