c5: cell chemistry Flashcards

Question

Which type of reaction- anaerobic or aerobic produces more ATP and how many?

Answer 1

Anaerobic= no atp at first-> 2 ATP from glycolysis Aerobic= 34 ATP at first-> 2 ATP from glycolysis

Answer 2

1. Glycolysis 2. Krebs cycle 3. Electron transport chain

Answer 3

Releases energy from breaking down glucose without the presence of oxygen.

Answer 4

Lactate or alcohol

Answer 5

gives 2 more ATP and some other energy carrying molecules.

Answer 6

Pyruvic acid (glucose split into two) is broken into carbon dioxide in a series of energy-extracting reactions. Citric acid is created in this cycle.

Answer 7

It uses the high-energy electrons from the Krebs cycle to convert ADP to ATP, producing 32 ATP.

Answer 8

a long chain of amino acid

Answer 9

A chain of glucose (mostly)

Answer 10

Because it is used to regulate fluids in the body (osmoregulation with diffusion), aid metabolism, as well as nerve impulses.

Answer 11

Oxygen transport and turned into harmoglobin

Answer 12

- no energy value - essential for small amount to maintain good health - essentials cannot be created therefore must obtain from diet

Answer 13

37 degrees celsius

Answer 14

1. organic 2. co-enzymes

Answer 15

1. inorganic 2. cofactor

Answer 16

1. carbohydrates: compact storage of sugars 2. lipids: fats, 2x energy of carbs of the same mass 3. proteins: little energy is released when broken down

Answer 17

Temperature, pH of solution, concentration of substrate, concentration of enzyme

Answer 18

Pepsin and proteinase have an optimum pH of 2 and work in the stomach to breakdown protein.

Answer 19

- Enzymes are most active at optimum pH (most of the time it is 7 with exceptions) - Lose activity in low or high pH as the tertiary structure is disrupted- when enzymes denature, lose their 3D structure, and don't work.

Answer 20

- The rate of reaction increases as substrate concentration increases (at constant enzyme concentration) - Enzyme activity continues to increase until all of them are combined with substrate-> reaches maximum activity

Answer 21

Proteins: - increase rate of reaction by lowering energy of activation - catalyze nearly all the chemical reactions in the body cells - unique 3D shape that fit shape of reactants

Answer 22

They increase the rate of reaction by lowering the active energy required.

Answer 23

Homologous chromosomes

Answer 24

Alternating light and dark regions along the length of a chromosome. It shows where the genes are located on a chromosome.

Answer 25

1. DNA unzips when enzyme helicase breaks up hydrogen bonds on either sides of it. 2. Enzyme DNA polymerase III builds a new ladder on one of the two unzipped strands 3. Floating nucleotides are grabbed from around and stuck onto the lagging strand as Okazaki fragments 4. Two new strands coil up into the helix, but are still joined in the centre, known as a centromere

Answer 26

After one side of the double helix is formed, the other side is able to copy it for identical DNA.

Answer 27

When a DNA is triggered to replicate- S phase of mitosis and meiosis.

Answer 28

Phosphate, sugar, and base

Answer 29

Making new proteins by decoding DNA into language for proteins. - DNA contains genetic info to make amino acid - Where amino acids combine to make proteins.

Answer 30

Physical traits of an organism and control cellular function

Answer 31

Three bases that code for a specific amino acid triplet

Answer 32

Step 1: transcription DNA unzips, messenger RNA copies info from DNA using base pairings Step 2: genetic code is carried from the nucleus to the ribosome in the cytoplasm by tRNA Step 3: translation - Ribosome attaches to mRNA and starts reading the codons - Base pairings are translated into an amino acid chain by the tRNA, with an anticodon at its bottom pairing with the mRNA strand. - tRNA carries amino acids and attaches them to the growing amino acid chain - Once amino acid production is completed, the ribosome releases the amino acid chain. - Chain folds into a complex 3D shape to form a protein.

Answer 33

Make the protein better, worse, or no change. Better= actively selected for Worse= actively selected against No change= Won't be actively selected

Answer 34

- SIngle-stranded rather than double-stranded - it has a different molecule composition, where it has ribose instead of deoxyribose - it has different bases of uracil instead of thymine - it is shorter in length

Answer 35

Genetic mutation caused by a deletion or insertion in a DNA sequence that suits the way the sequence is read.

Answer 36

(top to bottom) circle, rectangle, 3 legs

Answer 37

It is on the tRNA and it bonds with the codon by matching with the complementary base.

Answer 38

When something goes wrong with transcription, translation or in the DNA replication itself.

Answer 39

Substitution and addition/ deletion

Answer 40

- codon is changed, but may not change the amino acid it codes for - if no impact on amino acid, no impact on produced protein - if has impact, could be pos/neg/ or neutral

Answer 41

When a base is added or deleted. - creates a frame shift - every amino acid after that is affected - this destroys the protein majority of the time

Answer 42

Protein= long chain of amino acid Fat= long chain of glucose

Answer 43

Because it conducts osmoregulation in the body as part of metabolism. (salt in the cell, diffusion, etc)

Answer 44

mono- single unit of sugar, simplest form of it di- 2 mono poly- many monos

Answer 45

- starch in plants - glycogen in animals

Answer 46

- A monomer is a basic unit of a substance - a polymer is many units of the monomer put together. (1 mark). Any relevant example, such as: glucose is a monomer for molecules such as starch and glycogen; or amino acids are monomers for proteins. (1 mark)

Answer 47

A triglyceride contains glycerol, 3 fatty acids

Answer 48

Chain of substances with polypeptide bond.

Answer 49

Structural: collagen Regulatory: insulin Contractile: actin Immunological: antibodies Transport: hemoglobin Catalytic: amylase

Answer 50

Region in enzyme that fit substrates.

Answer 51

Lock= enzyme, Key= substrate - 1 lock only fits 1 key - active site cannot change - wrong key (substrate) leads to no reaction

Answer 52

- enzyme is not rigid, changes shape with substrate - active site is not the exact same shape as substrate-> wraps around it instead - vitamin (coenzyme) comes in, changes active site and allows reaction to take place.

Answer 53

- a non-comp inhibitor has a different structure from the substrate - distorts the shape of the enzyme, altering shape of active site - prevents binding of substrate - cannot reverse by adding more substrate

Answer 54

- A comp inhibitor has a structure like the substrate - compares with substrate for active site - stops reaction by blocking active site and restricting substrate from entering - can reverse the effect by increasing substrate concentration

Answer 55

- turns into toxin - kills enzyme/ organism completely

Answer 56

When a product of the reaction binds to the active site of an enzyme and changes its catalytic activity.

Answer 57

- Each enzyme produces a product which acts as the substrate for another enzyme - After enough products are formed, an end product binds with the first enzyme and stops its activity. Enzyme on- need more Enzyme off- need less

Answer 58

- energy released when bonds holding atoms together break, usually as heat - used to form ATP from ADP - stored at ATP until needed

Answer 59

- used by all cells to carry out work - activities of organisms are the result of metabolism - used to build new molecules and break up old molecules

Answer 60

Organic: vitamin Inorganic: mineral Organic substances can be generated by the body where inorganic substances cannot.

Answer 61

Too much: of some may be harmful Essential for small amounts to maintain good health

Answer 62

- formed in body from carrotene - destroyed at high temp - maintain dim light vision

Answer 63

- Destroyed after prolonged cooking - Essential for wound-healing

Answer 64

- generated in skin from UV light - Essential for regulation of calcium and phosphate metabolism

Answer 65

- regulate body metabolism - healthy growth - necessary for construction of certain body tissues - needed in small amount

Answer 66

Calcium, phosphate, iron

Answer 67

Energy storage

Answer 68

- main source of energy - cellulose: fibrous material of Plant Cell Wall - dietary fibre: stimulates Peristalsis (contraction of muscles in digestive tract)

Answer 69

- stored as glycogen in liver & muscle - stored as fats under skin

Answer 70

- insoluble in water - soluble in organic solvent

Answer 71

- give energy - component of cell membrane - form fatty tissues under skin to store energy - acts as insulator to keep warm - to transport fat-soluble vitamins (A, D, E, K)

Answer 72

Broken down in the kidney to urea.

Answer 73

By formation of peptide bonds in a polypeptide chain.

Answer 74

1. Primary structure: The sequence of amino acids in a polypeptide chain. 2. Secondary structure: The shape of the polypeptide chain. 3. Tertiary structure: The overall conformation (shape) of the polypeptide caused by folding. 4. Quaternary structure: In some proteins, an additional level of organization groups separate polypeptide chains together to form a functional protein.

Answer 75

- Assist in enzyme activity - assist in performing necessary activity that the enzyme cannot perform alone

Answer 76

Prepares the active site for catalytic activity.

Answer 77

Mimic substrate, may block active site

Answer 78

They catalyze same reactions in different parts of the body.

Answer 79

Blood sugar-> many sugar around= kick start enzyme low sugar aorund= shuts enzyme

Answer 80

- cell wall peptide and penicillin have similar structure - mimics natural chemical to block enzyme - bacteria constantly redo cell wall as they grow and divide - Penicillin inhibits the enzyme that catalyses one of the reactions need to build a bond in the cell wall - causing weakness in wall - Osmotic pressure builds in the cell causing cytolysis (killing the bacteria)

Answer 81

Temperature: high temp= higher kinetic energy, therefore faster rate of photosynthesis Concentration of co2: higher concentration increase concentration gradient, therefore increase diffusion rate of co2 and rate of photosynthesis Light intensity: rate of photosynthesis will increase because there is more light available to drive the reactions of photosynthesis. Light quality: more sensitive in blue LEDs than red and green

Answer 82

- Biochemical process - Occurs in the chloroplasts of plant cells using light energy - synthesize organic compounds.

Answer 83

A BIOCHEMICAL process that occurs in different locations in the CYTOSAL and MITOCHONDRIA and METABOLIZES ORGANIC SUBSTANCES, AEROBICALLY or ANAEROBICALLY, to RELEASE USABLE ENERGY IN THE FORM OF ATP.

Answer 84

yeasts and some microorganisms, producing alcohol and co2

Answer 85

- Produced by muscles during rapid exercise - when the body cannot supply enough oxygen

Answer 86

Quick energy – - Lactic Acid fermentation is used to get quick energy and gives off lactic acid as a byproduct, thus the muscle pain. Long-Term Energy – - Cellular respiration to produce energy. - Exercising or activities that last for at least 15 to 20 minutes. - Best form for weight control.

Answer 87

DNA contains genetic info to make amino acids-> amino acids combine to make proteins-> proteins determine physical trait and cellular functions

Answer 88

Ribosomes in the cytoplasm.

Answer 89

- can be spontaneous - or caused by mutagens: high temp, uv light, chemicals, radiation

Answer 90

Nitrogenous base, sugar, phosphate

Answer 91

hydrogen bonds

Answer 92

Anti-parallel

Answer 93

Double helix formed from two complementary strands of nucleotides held together by hydrogen bonds between base pairs.

Answer 94

Reaction 1: - Respiration - takes energy from glucose and stores it in the phosphate bond to form ATP from ADP - anaerobic respiration yields 2 ATP while aerobic yields 36 Reaction 2: - Cell metabolism - phosphate group is removed, releasing energy - cell processes such as active transport, cell repair and mitosis - resulting ADP can then be recycled and used over and over again

Answer 95

- carbohydrates - contains glucose, which is a small, soluble molecule that passes cell membrane - long, compact chain structure - alternatively, respiration of amino acids produce toxic waste and lipids (e.g. triglycerides) that are poorly soluble in water.

Answer 96

- needed for building and repairing chemical structures - e.g. calcium is essential for building bones and teeth - needed for chemical reactions - e.g. assist enzyme function

Answer 97

Process: cellular respiration - Some oxygen is consumed as levels drop from 21 to 18% suggesting some aerobic respiration - Ethanol is an end product of anaerobic respiration in plants - this goes from 0 to 4 % anaerobic respiration must be occurring *- The airtight lid means restricted oxygen supply, so when this runs out the respiration will be predominately anaerobic

Answer 98

Factor A- graph A: Temperature or pH or Light at time of Day Reason: Temperature- ~ Photosynthesis increases until the temperature gets too high or too low ~ stomata close (to prevent water loss) and CO2 availability decrease therefore less photosynthesis OR – slow molecular movement so enzyme substrate collisions are low. - As temp increases, collision rate increases - eventually denaturing reduces the effectiveness of collisions until no collisions are effective - P/S ceases. Similar argument for pH Light/Time of day – Photosynthesis with available light (intensity) during the day and will not occur in the dark. Factor B (Graph B): Carbon dioxide or a substrate/reactant in P/S or light (in laboratory conditions)

Answer 99

- Measuring the inputs and/or outputs of photosynthesis - Change in Co2 and o2 could be measured - in an enclosed container holding the plant OR - increase in plant tissue could be measured as new growth comes from photosynthesis. - Both gases need to be measured with the plant in the dark to give a baseline comparison of cellular respiration’s effect

Answer 100

Enzymes active site binding to a specific substrate.

Answer 101

- Specificity achieved by unique shape of the active site formed in the protein structure - Which induces a fit with substrate Protein structure – enzymes active site – substrate – induced fit. (1/2 mark each)

Answer 102

2 marks for lemon juice explanation; ½ mark for each suggested treatment (explanation not required) - Lemon juice = acid, lowers the pH in the area of the cut - enzymes rate of reaction varies with pH ∴ adding acid means its no longer at optimum pH - ∴ rate of reaction is greatly reduced Two other treatments: - heating/cooking OR cooling/freezing - temperature no longer optimal for enzyme function OR - add an enzyme inhibitor that would block or compete with the active site - reduce substrate concentration (e.g. oxygen) by vacuum sealing etc

Answer 103

- MITOCHONDRIA produce ATP to supply the energy needed for the production of protein on the ribosomes of the Rough Endoplasmic Reticulum (RER). - Membrane-bound ribosomes in the RER translate the mature mRNA transcript into amino acids that are attached to become polypeptides - GOLGI BODIES modify protein by the addition of carbohydrates and lipids. - CHLOROPLASTS form glucose to act as the energy source.

Answer 104

(shape) Reason: - Shape B is shaped so that it could be induced to fit in the active site - so block /compete with the normal substrate ½ mark for block/compete/etc. ½ mark for induced fit

Answer 105

Process: TRANSCRIPTION Description: - DNA (unlabelled) is located inside the nucleus. - DNA is a double helix polymer of nucleic acids containing the GENETIC CODE. - The DNA strands partially separate and one strand acts as a TEMPLATE to produce many small strands of MESSENGER RNA (labelled Q). - The gene coded by a short segment is transcribed into mRNA. - COMPLEMENTARY BASE PAIRING (A-T or A-U & G-C) ensures the FIDELITY of the genetic code. - The mRNA then LEAVES THE NUCLEUS through the pores in the nuclear membrane.

Answer 106

Process: TRANSLATION Description: - tRNA (labelled E) carries a specific AMINO ACID (labelled F) dependent upon the ANTICODON (labelled G) they possess. - The anticodon on the tRNA COMPLEMENTS the CODON (unlabelled) on the mRNA between the large and small subunits of the RIBOSOMES (labelled S). - As tRNA binds to its complementary codon, the amino acid it carries adds to the lengthening POLYPEPTIDE chain. - Ultimately, the code found in the gene of the DNA translates into a polypeptide (protein). - The protein produced possesses some biological function. - Complementary base pairing of codon to anticodon again ensures fidelity of coding and a specific polypeptide is made according to the genetic code found within the DNA.

Answer 107

- A non-competitive inhibitor binds to the enzyme (½ mark) which is not the active site (½ mark) - This changes the shape of the enzyme molecule (denatures it) and thus the shape of the active site (1 mark). - As a consequence, the enzyme can no longer function to catalyse the reaction (½ mark) because the substrate no longer fits into the active site (½ mark).

Answer 108

Complementary bases of coding strand but in RNA format (U instead of A)

Answer 109

- The function of the coding strand is for DNA replication. - DNA unwinds and the non-coding strand is matched with complimentary bases to form a new strand.

Answer 110

- Structure X is mRNA (½) - mRNA codes for a specific protein therefore the length of mRNA depends upon the protein (series of amino acids) it is coding for - mRNA has codons that attract the anticodons of structure Y with their complimentary bases (1). - Structure Y is tRNA (½) - tRNA has an anticodon as well as an amino acid attachment site (½) - When matched with the mRNA, tRNA brings the amino acid it codes for. - The amino acids bond together (peptide bonds) to form a polypeptide chain or protein (1).

Answer 111

Point A factor: CO2 concentration (½). Reason: - As the CO2 concentration increases the rate of photosynthesis increases on the graph. CO2 is used up in the reaction. CO2 is a reactant in photosynthesis (2 marks for 2 points). Point B factor: Could be any other factor (light intensity, temperature, enzyme concentration, number of chloroplasts) (½). Reason: - The graph indicates that at point B increasing CO2 does not result in an increased rate of photosynthesis. - Therefore, some other factor must be limiting the rate of photosynthesis. - E.g. Lack of light intensity means that there is not sufficient energy from sunlight for the reaction to proceed. Increase in temperature increases kinetic energy of molecules therefore rate of reaction (2 marks).

Answer 112

- Aerobic respiration happens in the presence of oxygen (½). - It produces 38 ATP (½) and no toxic bi-products (½). - Anaerobic respiration occurs when no oxygen is present (½). - It only produces 2 ATP (½) and ethanol (½). - When the roots do not have access to oxygen their anaerobically respire and therefore produce less energy in the form of ATP. They need the ATP to power active processes (½). - Without sufficient ATP they will not be able to transport minerals across the cell membrane and hence the cell will die (½). - Ethanol is toxic to the plant and will therefore kill the root cells (1)

Answer 113

1-1.5 marks: What happens to p/s and res in low light e.g. In low light conditions, the rate of respiration would be greater than the rate of p/s, meaning very little excess oxygen is produced, therefore 02 levels may fall 1-1.5 marks: What happens to p/s and res rate as light increases e.g. as light intensity increases, there is an increase in p/s converting co2 to glucose and oxygen 1 mark: acknowledging res rate does not change

Answer 114

- mostly likely complimentary (lock and key or induced fit) - of enzyme's active site - as it has similar shapes to active site - the other enzyme's active site lack some of the shapes required to bind to active aite of enzyme molecule - other enzymes have different charges

Answer 115

- competitive inhibition - use of drug would block/ inhibit the active site of ACE or compete with Angiotensin I - Inhibiting production of angiotensin II - Blood raising agent would not then be released - leading to reduced blood pressure

Answer 116

mRNA: UCG, AAG DNA: AGC, TTC

Answer 117

- tRNA has an amino acid attachment site and an anticodon region - tRNA have anticodons complementary to codons on mRNA, which code for specific amino acids - tRNA carrying the amino acid attaches to the ribosome and bring in amino acids to the mRNA - once anticodon-codon binding occurs on the mRNA, peptide bond is formed leading to polypeptide chain formation.

Answer 118

- ATP is the preferred source of energy for metabolic processes as only one bond needs to be broken for a net release of energy, (ATP RELEASE FORMULA) and it is a recyclable molecule - cellular respiration allows ATP to reform by adding a phosphate molecule to the ADP. This can accommodate a net 36 ATP if aerobic or net 2 ATP if anaerobic - Initially from 1-15 sec: muscle cell derives energy from breaking available ATP -> ADP+Pi+energy - 15-20 sec: after ATP is depleted, free glucose then broken down via cellular respiration to provide more ATP. - 20-140 sec: glycogen (stored in liver and muscle cells) breaks down into glucose, triggering ATP production via cellular respiration.

Answer 119

- Increasing the amount of enzyme will increase the rate of reaction - This is because there are more active sites for the reactions to take place in.

Answer 120

- optimum temperature: 37 deg - optimum ph: 7 - At its optimum condition, enzyme reaction will occur at its fastest rate

Answer 121

- enzyme would denature and lose its 3D structure - active site will change site- no long fits substrate - therefore catalytic reaction would pause

Answer 122

- increased reaction rate as it warms up - enzyme initially has low temperature therefore kinetic energy is decreased - therefore slow initial reaction rate

Answer 123

Changes the protein structure

Answer 124

- Q is likely to be a non-competitive inhibitor (1). - It binds to an alternate/allosteric site on the enzyme (½) - - - - and causes the active site to change shape (½). - This means it will no longer be able to induce a fit (be a complementary match) for the specific substrate (½) - and as a result the enzyme’s function to catalyse a reaction will be reduced (½).

Answer 125

- Lipase’s active site means it will only work to break down lipids due to the specific structure of lipid substrate (1). - ------- Lipase has optimal working conditions (½). - Specifically, this is 37 degrees C/body temperature (½). - Bile produces optimal pH conditions for lipase (1) being slightly alkaline. Beyond these optimal conditions, lipase may become denatured changing the active site shape and reducing enzyme function (½)

Answer 126

- Molecule one is ATP (adenosine triphosphate) as it has three phosphate groups - molecule two only has one phosphate group and is likely to be a nucleotide

Answer 127

- The high energy, terminal phosphate bond releases energy in a useable form; * Only one bond needs to be broken to release energy; * ATP/ADP and Pi are recyclable, so energy is always available to the cell; or * ATP is soluble so can easily diffuse from the mitochondria to all parts of the cell to provide energy.

Answer 128

- Photosynthesis is undertaken to convert CO2 + H2O into glucose, in the process converting light energy into chemical energy (1) that the plant can store glucose as starch or make cellulose to build plant tissues (1). However, ATP is also needed for cells to undertake processes such as active transport, protein synthesis and cell division (1). Therefore, the plant is able to take the glucose made from photosynthesis and use it in cellular respiration to make ATP available for cellular processes to sustain life (1).

Answer 129

The graph measures the rate of photosynthesis (PS) by CO2 consumption (an input) and the rate of cellular respiration (CR) by CO2 production (an output) (1). Any of the following or other logical response to cover the points outlined: * CR remains fairly constant over the 24-hour period, only slightly elevated in daylight hours (1) * the elevated period between 9am and 6:30pm would support needing more ATP for photosynthetic reactions (1) * Increasing temp increases rate of CR (1) * PS only occurs in daylight hours from 7am to 7pm, peaking at 3pm (1). * Light intensity changing during the day (I). * PS peak is more than double that of CR, showing that although it occurs across a smaller time period (12 hours) compared to the 24hrs of CR, PS still exceeds the rate of CR. This is needed for plants to be able to grow (1). * Compensation points shown at approx. 9am and 7pm is where the amount of CO2 used in PS equal the amount produced in CR, therefore this is where the rates of both CR and PS are the same (1).

Answer 130

DNA * Double helix made up of thousands of nucleotides * Double stranded containing a long chain of nucleotides (bases) made up of TAGC * Contains genetic material that acts as a ‘blueprint’. ------- * Contains genes which code for proteins * Unravels to expose gene sequences * Used as a template to make a molecule/strand of mRNA in the nucleus as part of transcription tRNA * Folded single strand of nucleotides. * Single strand of nucleotide with an ‘L’ shape with ribosomal binding arm and anticodon loop * Has an anticodon that is a complimentary match for the mRNA codon * Has an anticodon with corresponding amino acid (aa) attached ---- * Carries a corresponding amino acid (aa) to the ribosome as part of translation in protein synthesis * It binds to one of three sites on the large subunit of a ribosome * Carries an amino acid (aa) to form the correct sequence of polypeptide chain mRNA --- * A single strand of nucleotides * Unstable and short single strand of nucleotide corresponding to a gene encoded within DNA * Created in the nucleus to make/take a copy of genetic code for a gene then move to the cytoplasm/ribosome to be decoded * Transcribes genetic information from DNA in the nucleus to the cytoplasm/ribosome where proteins are synthesised – read and decoded in translation * It transcribes sections of the DNA code in nucleus - via transcription and moves to a ribosome where the codon matches an anticodon of tRNA with a corresponding amino acid to form a polypeptide chain – via translation

Answer 131

Mutation 1 - A nitrogenous base has been deleted, thus creating a ‘frameshift’ (codons are read in groups of 3’s) and therefore causing every codon sequence past the point of mutation is shifted. The change in sequence changes the amino acids within the mutated strand resulting in a change in the polypeptide/protein composition (change in shape of protein thus altering the intended function). Mutation 2 The change of the 3rd codon from GGG to GGU (point mutation – substitution) still results in the same amino acid in the same place within the sequence. This is a ‘silent’ or neutral mutation and has no overall effect on the polypeptide chain or protein formed. Mutation 3 The change of the 9th codon from UAA -a stop amino acid to UAC -tyr / Tyrosine (point mutation – substitution) means that the polypeptide chain / protein would not be completed and more amino acids will possibly be added. Resulting in a longer chain and a different protein.

Answer 132

G A G C A T T A G C C G

Answer 133

This will change the AA coded for GGC codes for GLY (1/2) and GAC codes for ASP(1/2). This change in AA may alter the way the polypeptide chain may function(1/2), it may be beneficial, negative or neutral. (1/2)

Answer 134

This would result in a frame shift(1/2) pushing all the other codons out of line altering every AA after this insertion(1/2). This will have a large (1/2) impact on the protein and most likely it will not work anymore.(1/2)

Answer 135

Causes all enzymes in milk and any bacteria living in the milk to denature (1/2) This changes their 3D structure (1/2) and therefore not be able to work,(1/2) effectively killing any organisms in the milk. (1/2)

Answer 136

The mRNA enters the ribosome (1/2) that reads the first three bases called a codon or triplet(1/2). It matches the codon on the mRNA with the complementary Anti codon (1/2)on tRNA which carries the AA(1/2). As the next codon is read that AA is connected to previous AA by a peptide bond.(1/2)

Answer 137

35 degrees is the optimum temp (1) for enzyme activity so allows organisms in this case bacteria (yogurt culture) to grow / carry out chemical reactions(1/2) and ferment the milk(1/2). (side note: bacteria ferments the Lactose in milk to make lactic acid which acts on yogurt protein to give it a thicker texture, don’t need this to get marks)

Answer 138

1) Plant 1 – complete darkness (2 marks) CO2 levels will go up and O2 levels will go down (1) as the plant continues to respire through cellular respiration.(1) 2) Plant 2 – 12 hrs light , 12 hrs, darkness ( 2 marks) During the 12 of light CO2 levels will go down and O2 go up due to photosynthesis (1/2) occurring at a higher rate than respiration (1/2) and during the 12 hrs of dark you will see a drop in O2 and a rise in CO2 as it is still respiring.(1) 3) Plant 3 – 24 hrs light (2marks) During the 24 of light CO2 levels will go down continually and O2 go up continually (1) due to photosynthesis occurring at a higher rate than respiration (1) all the time.

Answer 139

1) Plant 1 – (complete darkness) (2 marks) The oxygen levels would drop continually and CO2 rise continually as both the plant and mouse are respiring. (1) Eventually the mouse could die due to lack of oxygen and too high a CO2 levels (1) 2) Plant 2 – (12 hrs light , 12 hrs, darkness) ( 2 marks) You would still see in the 12 hrs of dark a drop in O2 and a rise in CO2 (1/2) as both the plant and mouse are respiring (1/2). During the 12 hrs of day you would likely see an increase in oxygen depending if the plant is big enough to produce more oxygen than the plant and mouse are using (1) 3) Plant 3 – (24 hrs light) ( 2 marks) Most likely you would see oxygen levels go up and carbon dioxide levels go down (1/2) as the plant can photosynthesis continually(1/2). But it would be at a much slower rate than a) 3) (1/2) as it also has the mouse respiring (drops oxygen, rises carbon dioxide) to offset as well. (1/2)

Answer 140

The triangle is acted on by enzyme 1. - Enzyme 1 will continue to act on this substrate breaking it down continually until it is run out or at very low levels unless it is stopped by an inhibitor. - By having the end product of a multiple step reaction inhibit the first stage you will get substrate being broken down for a time while it goes through all other steps until it reaches the end. - The final product then stops the first process insuring not all of the substrate is broken down. - This give the cell control over how much of a substance is broken down.

Answer 141

By cooling the mixture too far the enzymes in the yeast are not working at optimum rate so nothing would happen for the first 4 days. Has he heats it up kinetic energy increases and more chance of substrate meeting active site so reaction will increase. Beer will still be made but slower than 3.

Answer 142

GCU coded for Ala while UCU (mRNA) codes for Ser this could change the protein for better, worse or not at all.

Answer 143

This creates a frame shift changing all the AA’s after the insertion this will change drastically changing the protein. Most likely making the protein not work any more.

Answer 144

0 ppm as no gas exchange is allowed there fore no carbon dioxide can enter the plant through the stomata and converted into sugar.

Answer 145

- reversible inhibitation - Adding more substrate will dislodge a competitive inhibitor allowing the enzyme to keep working.

Answer 146

Optimum pH means it will work most effectively in stomach with a Ph of around 2.

Answer 147

Pepsin found in the stomach would work most effectily in stomach environment of pH of around 2, as it leaves the stomach bile neutralises the acid bring the pH up. As it goes from 2 – 7 lipase will work most effectively around 7 as the bile makes the small intestine slightly alkaline trypsin reaches it optimum pH of about 8.

Answer 148

* Polymers are made up of many repeated units -monomer e.g. proteins are made up of many amino acids. * Triglycerides are not made up of repeated units (monomers). They are composed of glycerol and 3 fatty acids (which may or may not be the same composition).

Answer 149

Protein molecules are composed of the elements carbon C, hydrogen H, oxygen O and NITROGEN. Cabohydrates and lipids are composed of C, H and O and no nitrogen, making nitrogen content of the food eaten a reliable measure protein intake.

Answer 150

Plant cells contain protein but it is locked behind a cell wall of cellulose. Humans lack the enzymes to digest the cellulose. Mechanical destruction (e.g. chewing) of the cell wall is the only way to release the cell contents and make the protein available for digestion followed by absorption of the amino acids. There will be a higher nitrogen content in the faeces of a vegetarian because it will contain a higher fibre (cellulose) content making the digetibility coefficient lower. Meat is composed of animal cells that are easily digested as they lack a cell wall, hence more protein is available for digestion.

Answer 151

* Rate at which oxygen is produced * Rate at which cabon dioxide is used * Rate at which glucose (or starch) is produced

Answer 152

Photosynthesis is a series on several reactions all controlled by enzymes. Enzymes all have an optimal temp so if the temperature varied from group to group that would effect how quickly they could photosynethesise.

Answer 153

Disagree with the student (1 mark) there must be some photosynthesis occurring between 0 -100 as the oxygen level is changing(1/2). Respiration will stay fairly much constant (1/2 mark) so you would assume if no photosynthesis occurring than Oxygen production rate would stay at -100 (1/2) but as it is rising it must be starting to photosynthesize just not enough to offset the amount of oxygen used in cellular respiration (1/2)

Answer 154

Light is no longer a limiting factor so increasing it will not increase photosynthesis. The rate is being limited by other factors such as amount of Carbon dioxide or number of palisade cell or amount of water.

Answer 155

Mutation 1 AUG CU GGG AAU GCA CAG AAA GAC UAA AUG CUG GGA AUG CAC AGA AAG ACU AA aa* Met Leu Gly Met Leu Arg Lys Thr X A nitrogenous base has been deleted, thus creating a ‘frameshift’ (codons are read in groups of 3’s) and therefore causing every codon sequence past the point of mutation is shifted. The change in sequence changes the amino acids within the mutated strand resulting in a change in the polypeptide/protein composition (change in shape of protein thus altering the intended function). Mutation 2 AUG CUC GGU AAU GCA CAG AAA GAC UAA aa* Met Leu Gly Asp Ala Glu Lys Asp A stop The change of the 3rd codon from GGG to GGU (point mutation – substitution) still results in the same amino acid in the same place within the sequence. This is a ‘silent’ or neutral mutation and has no overall effect on the polypeptide chain or protein formed. Mutation 3 AUG CUC GGG AAU GCA CAG AAA ,,GAC UAC aa* Met Leu Gly Asp Ala Glu Lys Asp A Tyr The change of the 9th codon from UAA -a stop amino acid to UAC -tyr / Tyrosine (point mutation – substitution) means that the polypeptide chain / protein would not be completed and more amino acids will possibly be added. Resulting in a longer chain and a different protein.

Answer 156

The function of the coding strand is for DNA replication. DNA unwinds and the non-coding strand is matched with complimentary bases to form a new strand.

Answer 157

Messenger RNA conveys the genetic information from the DNA by producing a complimentary copy of the original strand of DNA and transporting it out of the nucleus to the ribosomes where it forms a template for amino acid sequence in the production of proteins.

Answer 158

An amino acid is determined by its codon(1) therefore a change in codon produced by point rotation/chemical/environmental damage DNA during replication OR an error in transcription in the mRNA nitrogen bases OR an error in translation when codon and anticodon are not a correct match resulting in a changed amino acid/protein. (need to have any of those 1 mark each)

Answer 159

factors: light intensity, water, availability, carbon dioxide temperature, colour, lights duration light intensity: light is needed for photosynthesis, particularly at the red and blue ends of the spectrum, which green plants use balance between maximising photosynthesis, and not overheating the plants and drying them out. Place in the greenhouse so that it maximise the light availability and not in the shade, good optimised growth of the plants, using artificial lights at night water availability is needed for photosynthesis. Humidity levels need to be controlled to help restrict access. Water loss will not promoting mode etc for either optimising by using sprinklers or some other irrigation method to ensure correct amount. Carbon dioxide is needed for photosynthesis. It is required for the production of glucose that is used to produce ATP for metabolic processes, increasing carbon dioxide levels can therefore, increase growth rates . could be pumped into a close greenhouse. Temperature: all metabolic processes are affected by temperature, including photosynthesis. So needs to be optimised, too hot and the plants enzymes may nature, or the rate of transpiration may increase resulting in closing of stomata, which will reduce the rate of photosynthesis.

Answer 160

difference: energy is captured by photosynthesis in form of light, but released by respiration as ATP and heat. photosynthesis, has two stages, light and dark and aerobic respiration. respiration occurs in the mitochondria, photosynthesis occurs in the chloroplasts.

Answer 161

Energy can be obtained easily through breaking the phosphate bond (atp-> adp + p) is a recyclable molecule small convenient amounts of energy can be delivered to where the energy is required in the cell. (avoids waste atp is a quick usable form of energy compared to aerobic respiration of glucose (only one bond needs to be broken to release useable energy)

Answer 162

they both have a different level of pH where the activity of the enzyme is optimal as a river buffalo enzyme , being efficient with pH 7-8, while the bacterial enzyme is efficient at a lower pH range 5 to 6.6. This is because the organisms live in different environments, the bacteria lives in hot Springs that are likely to be acidic and the water Buffalo has a stable internal environment of approximately pH 7.

Answer 163

The initial response is very rapid as there is plenty of substrate to collide effectively/bind with the active side of enzyme. But the rate of conversion plateaus as the amount of enzyme become a limiting factor when all the active sites are full and the enzyme is operating at maximum rate.

Answer 164

in the induced fit model, the exposure of the enzyme to the substrate causes the active site of the enzyme to change shape. In order to allow the enzyme and substrate to bind and form an enzyme-substrate complex. This lowers the activation energy required for conversion of substrate products reducing the time it would otherwise take, OR just allows the enzyme to be free to catalyse other reaction in an incredibly short time.

Answer 165

All organisms require essential amino acids that cannot be made by the body/must be provided by a digestion/diet. These are needed to produce proteins, which has a wide range of essential functions within the body in the cells, for example, in cell membranes, enzymes, muscles, etc. Without getting enough essential amino acids and the body would suffer from this deficiency.

Answer 166

People need to ensure they eat enough protein in the regular diet so they don’t need to keep eating extra fruit with extra kilojoules to meet the essential amino acid requirements. This will reduce the amount of carbohydrates and fat they feel they need to eat and reduce the likelihood of obesity with its consequent health issues.

Answer 167

They appear green because they absorb all other light and reflect the green light to our eyes therefore appearing green. This means that other colours are absorbed these all give a higher rate of photosynthesis.

Answer 168

Again the yellow is reflected and not absorbed. As yellow like green gives a low photosynthesis rate it would not have too much of a detrimental effect on plant growth. As the other light spectrums all give a higher rate of photosynthesis.

Answer 169

Shows that the presence of enzyme reduce the activation energy required to go from glucose to product molecule. Without the enzyme more energy is required for the same reaction to take place so with the enzyme the reaction will occur quicker.

c5: cell chemistry Flashcards

(199 cards)