lab test 2

Question 1

fermentation

Answer 1

does not require oxygen
oxidizes NADH
produces ehtanol or lactate
pyruvate is reduced (primary electron acceptor)

produces less ATP per glucose, so rate of consumption of glucose is higher. Cell moves from aerobic to anaerobic must consume 15 times mote glucose than in aerobic (2 vs 30)

produces CO2 and ethanol or just lactate

Question 2

Fermentation lab

Answer 2

measjre the increase in pressure due to CO2 given off

glucose, sucrose, maltose and lactose fed to yeast
control is water

respiration measurments, oxygen uptake is measured from germination pea seedlings with starch as the main food supply
soda lime between sensor and peas to absorbe CO2 produces, as then there would be no change in pressure (1: 1 ration)

Surrounded by l’aluminium to prevent photosynthesis and production of O2, WOULDVE disturbed the studied consumption of O2

Question 3

different saccharides yeast consumption

Answer 3

glucose and fructose is nomrmal to metabolize

most enzymes have the enzyme sucrase, so they can digest it by breaking it down into glucose and sucrose, digestion is just as well as glucose

few molecules of maltose can enter the cell. once they enter the cell, theur presence stimulates the synthesis through transctiption anf translation of the enzyme maltose permease/maltase for transport and digestion. then rapid entry is allowed. this is called lag period. Maltose is then hydrolyzed into two glucose (induction) (gene is turned on when maltose is present)

lactose is not usually in environment of yeast, so yeast does not usually produce enzymes to metabolize it

Question 4

advantage of only hydrolyzing maltose when needed

Answer 4

saves energy of not producing enezymes not needed

able to adapt to its environment.

Question 5

RQ

Answer 5

respiratory quotien, CO2/O2
depends of substrate being used

Question 6

specific rate units

Answer 6

gas per minute/gram yeast

Question 7

mesophyte leaf structure

Answer 7

moderate habitat
vascular bundle with xylem (top) and phloem (bottom)
epidermis and cuticle (prevents evaporation)
mesophyll, contains chloroplasts. primary photosynthetic tissue, has palisade mesophyll: near the top. and spongy mesophyl: lots of intercellular spaces
stomata contains guard cells and pores, CO2 does in, O2 goes out
stomata on the underside of leaf

Question 8

regulation of water loss

Answer 8

done in sotmata
transpiration, water gets out and through diffusion new water form soil comes in, rich in minerals
guard cells will close if water loss is too much. they become flacid and close. when there is enough water in plant, guard cells become turgid and stay open to allow water to get out. controlled by intercellular osmolarity

osmorality of guard cells greater than the surroundings, guard cells open and allow tranpiration

Question 9

xerophytes

Answer 9

very dry climate
has a bigger cuticle
multilayer epidermis
stomata on lower surface of leaf to prevent drying out by the sun
specidlized pits with epidermal hairs

Question 10

hydrophytes

Answer 10

life in water
stomata in uper epidermis only to increase transpiration (if under, will be exposed to less sunlight and will dry out slower)
thin cuticle (do not experience much water loss)
chloroplast in epidermis
large air chambers in spongy mesophytes for buancy

Question 11

pigments

Answer 11

substances which absorb visible light of certain wavelenghts while reflecting other wavelenghts

primary pigments are chlorophyll a (blue ish) and b (green) is accessory pigment, they absorb best red light

secondary as xantophylls and carotenes

light energy absorbed by pigments puts the electrons in a momentary excited state, allowing the plant then to synthesied carbohydrates.

Question 12

carotenoid pigments

Answer 12

xantophylls: yellow
carotenes: orange

equiped with them to absorbe a large eange of wavelenghts for photoynthesis

also protect leaf from light energy that can damage it by absorbing and dissipating light energy

Question 13

seperation by chromatography

Answer 13

based on solubility

adsobent: sheet, stationary phase, more polar, here cellulose in paper
eluent: solvent, mobile phase, less polar

more polar it is, more time it will spend in the stationary phase, less it will travel

order is chlorophyll b, a, xantophyll, carotene

Question 14

absorbtion spectra

Answer 14

400nm -700nm

The set of wavelengths absorbed by a pigment

drops at green to organge part of light

The range of light that a plant uses for photosynthesis is its absorbtion spectrum

a plot of efficiency of different types of wavelengths in bringing about the photosynthesis is action spectrum

action spectrum is a graph that shows the rate of photosynthesis at different wavelengths of light

absorption spectrum is a graph that shows the absorbance of different wavelengths of light by a particular pigment, specific to a pigment

Question 15

restriction enzymes preventing phage infections

Answer 15

phage will infect bacteria by injecting nucleic acids into cell and hijaching bacterial DNA to make new viruses then bacteria will lyse to release a bunch of new viruses (lytic cycle)

restriction endonucleases break the phosphodiester bonds that link nucleotides. acts as scissors. exonucleases then digest the ends of the DNA molecules.

endonuclease cut at specific sequences called recognition or restirction sites

does not cut the bacterias own DNA beome it is methylated, so endonuclease cannot bind to it.

Question 16

usage endonuclease in biotech

Answer 16

recombines DNA of same or different organisms (genetic code is universal) with the help of enzyme ligase

to e recombined, different DNA have to be cut by the same nuclease

DNA will reannel themselves to other fragments with sticky ends that are complimentaty to their own sequence

cuts mutate genes

used in paternity tests

Question 17

sticky overhang vs bunt no overhang

Answer 17

sticky overhang is done when endonuclease cleaves at different sites in both DNA strands, creating an overhang. allows for recombinant DNA.

blunt cleves at the same site

Question 18

gel electrophoresis

Answer 18

gel is agarose, molecules will travel furhter depending on their difference in charge, size and shape. in DNA, size and shape is what actually matters, because they are all negatively charged

travels from negatovely charged end to positvely charged end because dna negatively charged

if two cuts have the same size, there isnt 2 lines, just one at the ladder

supercoiled DNA will travel furthest thanks to its conformation

cicular plasmid will travel less, it is large and floppy

linear plasmis will usually travel a bit more than circular, the shorter it is, the ruther it will travel

usage of lader helps knowing the lenght of a cut plasmid

Question 19

transgenesis

Answer 19

add a foreign gene to an organism and alter a phenotype

once added, genome will be transfered through vetical gene transfer, adding the gene to the population

agriculture, genes coding for traits such as frost, pest, or spoilage resistance can be inserted into plants.

In medicine, gene therapy treats diseases caused by defective genes by inserting healthy copies of the defective gene in a sick person’s cells.

creates transgenic organisms

Question 20

horizontal gene transfer

Answer 20

bacterias take up genes from its environment and incorporate the genes into its genome, these bacterials are naturally competent

Question 21

plasmids

Answer 21

contains genes that are beneficial to cell survival in new envirnments

circular DNA

they are vectors (vehicles) for the amplification and transfer of genes.

DNA fragment can be added into a defined spot in the plasmid making it a recombinant plasmid. pGLO is an example that can be used to transfer the GFP gene

Question 22

pGLO

Answer 22

araC: gene expression regulatory protein, which will repress transcribtion in the absence of aribanose,
GFP: produces GFP protein, bioflurescence
bla: selectable marker, encodes for beta-lactamase enzyme, which will make it resistant to ampicillin

Question 23

operon

Answer 23

In bacteria, groups of related genes are often clustered together and transcribed into RNA from one promoter. These clusters of genes controlled by a single promoter are called operons.

gene regulation systems, regulates a clusters of genes and coordinate their expressions

A group of genes clustered together that are transcribed at the same time

genes in operon enxode proteins that have various functions in the same process

allows cells to respond to changing environments and prevent a wastefull overproduction of undeed proteins

bacteria contains operons

ex: arabinose operon

Question 24

procedure bacterial tranformation

Answer 24

collect E coli and tranfer to CaCl2 solution (used to neutralize negative charge of the DNA and letting it closs the cell membrane during heat shock, gelps DNA get in place)
put plasmid in +pGLO
transfer on ice, then hot water, then ice (heat shock increase permeability of cell membrane to DNA, opens pores wider to get some DNA in)
incubate (allows the cells to recover from shock and make the ampicillin resistant protein)
plate

Question 25

controls

Answer 25

-pGLO contains no plasmids, just bacteria, serves as a control of the bacteria present.

+pGLO amd ampicillin is to Identify transformed bacteria

Question 26

promoter

Answer 26

Specific sequences along the DNA mark where transcription of a gene begins and ends. The DNA sequence where RNA polymerase attaches and initiates transcription is known as the promoter

The main function of a promoter is to bind transcription machinery and initiate transcription.
promoter, where RNA polymerase attaches to the DNA and begins transcription of the gene.

Question 27

arabinose

Answer 27

When arabinose is present in the environment, bacteria take it up. Once inside, the arabinose interacts directly with arabinose operon and the interaction causes the transcription of the genes downstream from the promoter, normally these are three digestive enzyme genes.

When the three enzymes are produced, they break down arabinose, and eventually the arabinose runs out. In the absence of arabinose the transcription is shut off.

in pGLO plasmids, these digestive genes were replaced with flurencent genes

Question 28

Why is that sucrose and glucose are fermented euquallh efficiently

Answer 28

Bacteria has the enzyme to catalyze sucrose into glucose, but it’s an enzyme reaction so it’s immediate

Question 29

Water control fermentation

Answer 29

Production of Co2 is all the reaction studied

Question 30

Chlorophyll à and b

Answer 30

Same everything except b has a carboxylique acid

Question 31

Why is the action spectrum and the chlorophyll a absorption spectrum different

Answer 31

Action spectrum includes the other pigments

Question 32

Controls lab 8

Answer 32

• pglo lb: lawn expected to be seen, if not, then growth is affected by something else than amp, ex heat shock
• pglo lb +amp: nothing to be seen, proves that original E. coli isn’t resistant to the amp.

Why not lawn on +pglo +amp? Not all we’re transformed
+ pglo + amp doesn’t have arabinose, binds to DNA which changes the conformation and activates the transcription factor of GFP (inducible gene)