Exam 2- Gen bio

kinetic energy

energy of movement, breaking bonds

potential energy

energy stored in the bonds

law of conservation of energy

energy cannot be created or destroyed, but can be changed from one form to another

law of thermodynamics

energy cannot be transferred from one form to another without the loss of usable energy

total energy

unusable energy + usable energy

enthalpy

free energy (usable G) + (entropy (unusable) x absolute temp)

orient substrate

a way enzymes can lower activation energy by putting molecules in the right position to bond them

induce physical strain

lowering activation energy- stretching bonds to be able to produce chemical reactions

alter chemical charge of substrate

lowers activation energy

negative delta G

free energy is release

positive delta G

energy has been added

what affects enzyme regulation

environment, factors and inhibitors

environment regulation

pH and temperature

factor regulation

inorganic ions
coenzymes- carbon containing molecules
prosthetic- permanently bound (hemoglobin)

irreversible inhibitors

covalently bonds with enzyme and shuts off activity

competitive reversible inhibitors

competes for the same active site with substrate

non-competitive reversible inhibitor

inhibitor binds somewhere other than the active site, changes the shape of the active site so substrate cannot bind

cellular respiration equation

C6H12O6 + 6O2 → 6CO2 + 6H20 + energy

oxidation

loss of an electron

reduction

gaining an electron

what do enzymes do in releasing free energy

helps to not lose as much energy to heat (stair graph example)

redox reactions

one compound getting oxidized, one compound getting reduced

two co-enzymes

1. NADH
2. FADH

glycolysis

1. energy investment phase
2. energy harvesting phase

energy investment phase

glucose is oxidized and an investment of two ATP molecules to result in 2 glyceraldehyd 3-phosphate and 2 ADP

energy harvesting phase

4 ADP+ NAD+ (reduced)+ 2G3P ---> 2 pyruvate + 4 ATP + 2 ADP

how much ATP is yielded after glycolysis

2 ATP

substrate level phosphorylation

taking a phosphate and adding it to something else (adding a phosphate from G3P to ADP to form ATP)

steps of cellular respiration

1. glycolysis
2. pyruvate processing
3. krebs/citric acid cycle
4. electron transport chain

pyruvate processing equation

2 Pyruvate + 2 NAD+ + 2 CoA → 2 Acetyl-CoA + 2 NADH + 2CO2
-NAD+ is reduced to NADH

krebs cycle equation

2acetylCoA + 6NAD+ + 2FAD + 2ADP --> 4Co2 + 6NADH + 2FADH2 + 2ATP

What does the Krebs cycle produce

4 ATP and lots of NADH

NADH

a high energy molecule that can be converted to energy in a later process

electron transport chain

a series of four protein complexes that couple redox reactions, creating an electrochemical gradient that leads to the creation of ATP in a complete system named oxidative phosphorylation.

where does all the oxygen go at the beginning of cellular respiration?

in the electron transport chain

ATP synthase

a system that pumps hydrogen back into the cell through an ion gradient to create ATP from ADP+ Pi

oxidation phosphroylation

oxidizing NADH and FADH, electrons go down to phosphorylate ADP+ Pi to ATP

how much ATP is yielded from electron transport chain

about 32 ATP

ATP yielded from cellular respiration

about 36 ATP
32 ATP from electron transport chain, 4 ATP from glycolysis

Two types of Fermentation

lactic acid fermentation and alcohol fermentation

lactic acid fermentation

pyruvate converted to lactate (cheese, yogurt, buttermilk, sour cream)

alcohol fermentation

Pyruvate converted to acetaldehyde by pyruvate dehydrogenase
acetaldehyde converted to ethanol by alcohol dehydrogenase
occurs in some bacteria and fungi
loses CO2

fermentation vs respiration

goal: covert glucose into energy
respiration: 32 ATP, needs oxygen
fermentation: 2 ATP, occurs when there is a lack of oxygen

Fermentation

Anaerobic- Life without air
NADH transfers electrons back to pyruvate
recycles NAD+ to be used again in glycolysis

photosynthesis equation

light energy + 6CO2 + 6H2O → C6H12O6 + 6O2

autotrophs

produce their own energy

heterotrophs

get energy from another source

light reactions

converts light energy into usable energy (ATP+ NADPH)
happens in the inner membrane of the chloroplasts in the stroma

light independent reactions

uses ATP and NADPH and CO2 from light reactions to make carbohydrates

chloroplasts

where photosynthesis occurs, 2 membranes and has its own DNA

electromagnetic radiation

- light
- gamma rays
- x-rays
- infrared
- radio waves

Photon interaction with a molecules (scattered)

photon bounces off

Photon interaction with a molecules (transmitted)

photon passes through

Photon interaction with a molecules (energy is absorbed)

molecule gains more energy, moves electrons out to another shell to hey to a higher energy level

pigments

absorb visible light

once molecule raised to another energy level...

1. releases energy as heat/ light
2. transfers molecules to another molecule
3. used for a chemical reaction

absorption spectrum

Non- cyclic electron transport chain

-occurs in the inner membrane of the chloroplast
- photosystem II absorbs so much light it gives electrons to another molecule (oxidizing agent) takes e- from H2O to make O2
- then given to photosystem I which is also absorbing light
- electron is eventually sent to where NADP+ is reduced to NADPH
- hydrogen is pumped back in through ATP synthase to produce ATP

cyclic transport chain

- only uses photosystem I
- e- always goes back to photosystem I
- can only produce ATP
- ATP synthase can still pump H+ back in to produce ATP

Calvin cycle reactions

1. CO2 fixation
2. CO2 reduction
3. regeneration of RUBP

CO2 fixation

RuBP + CO2 = 2(3PG)
Plants fix atmospheric carbon to form organic compounds

rubisco

enzyme used in CO2 fixation.
it is a carboxylase and oxygenase to fix carbon and oxygen (x10 affinity for CO2)

CO2 reduction

oxidation reduction reaction- ATP to ADP+Pi and NADPH to NADP+
- generates glycealdehyde 3- phosphate a high energy molecule that is easy for plant cells to generate carbohydrates

regeneration of RuBP

G3P converted to RuBP

every 3 turns of the calvin cycle produce...

1 G3P which is easily converted to fructose and other sugars

photorespiration

a metabolic pathway that occurs in photosynthetic organisms and releases carbon dioxide, consumes oxygen, and produces no chemical energy or food.

when hot- plant will lose water but stomata will stay close blocking CO2, concentration of CO2 will go down and oxygen concentration will increase

C3 plants

roses, wheat, rice, soy
CO2+ RuBP---> 2 G3P
- requires a wet, cool environment
- hot conditions have a lot of photo respiration

C4 plants

corn, sugar cane
- separated CO2 fixation by space
CO2+ PEP ---> oxaloacerate

CAM plants

Cacti
separated CO2 fixation based on time
Night: stroma is open CO2 is fixed to PEP by PEP carboxylase, taking in as much CO2 as possible
Day: stroma closes CO2 is released

steps of the cell cycle

1. reproductive signal
2. replicate DNA
3. genome segregation
4. cytokinesis

binary fission

the process in which prokaryotic cells divide

conditions for binary fission

ideal temperature, pH, energy source for a reproductive signal

prokaryotic cells

-single celled organisms
-circular DNA
- exponential growth

origin of replication in Prokaryotic Cell

- only one
- used to pull the chromosome to once side of the cell and splits the DNA

Eukaryotic cell division/ check points

G1, synthesis, G2, metaphase
- cannot pass to another checkpoint without passing the previous one

G1 phase/ synthesis

Growth and synthesis of DNA

G2 phase

ask: is all the DNA replicated?
more growth and development

metaphase

ask: are all the chromosomes aligned?
mitosis and cytokinesis occur

cyclin dependent kinase

protein required to progress through each checkpoint
adds phosphate groups to Rb (tumor suppressor gene)

unphosphorylated Rb

- active
- blocks DNA synthesis
- no phosphate groups are attached

phosphorylated Rb

-inactive
- DNA is synthesized
- phosphate groups are attached

cancer

constant phosphorylation can cause constant replication and unwanted growth (tumor/retinoid blastoma)

oncogenes

promotes cancer
example: HER 2 receptors are hyperactive which causes breast cancer

mitosis

cell division resulting in two daughter cells with the same DNA as the parent cell

DNA packaging

each strand of DNA wraps around a histones (protein complex) in a tight coil to form a chromosome

centromere

a specialized condensed region of each chromosome that appears during mitosis where the chromatids are held together to form an X shape

cohesion

proteins that hold sister chromatids together

interphase of Mitosis

G1, S, G2
cell is growing

centrosome

microtubule organization center
a cell in interphase has one centrosome
centrosomes double in the G2 phase

prophase

microtubule spindles form

prometaphase

nuclear membrane breaks down

metaphase

chromosomes line up at metaphase plate

anaphase

separating of sister chromatids

telophase

-nuclear envelope reforms
-chromosomes de-condense
-triggers cytokinesis

cytokinesis

pulls membranes together to split into two cells
- uses myosin and actin filaments

separase

cleaves the proteins that hold the sister chromatids together

meiosis

generates gametes (egg or sperm cells)
cells are not identical to the parent cell

somatic cells

any other cell in the body not including sex cells
2 sets of chromosomes, diploid (2n)

how many chromosomes do humans have?

- 46 chromosomes, 23 pairs
22 autosomes, 1 pair of sex chromosomes

gametes

sex cells
1 set of chromosomes, haploid cells