Bio 1105- test 2- Virginia Tech

thermodynamics

energy changes

Kinetic

energy of motion

potential

stored energy

Redox reactions

oxidation-atoms loses electrons

reduction-atoms gains electrons

1st law of thermodynamics

Energy cannot be created or destroyed

2nd law of thermodynamics

Energy cannot be changed from one form to another without a loss of usable energy

entropy- disorder

catalyst

substance that speeds up the rate of a chemical reaction

Active site

pocket in an enzyme where substrates bind and a reaction occurs

factors that influence enzymes

temperature, pH, concentration

metabolism

the total of all chemical reactions in an organism, some of which are aerobic reactions that require oxygen.

feedback inhibition

the end product of a metabolic pathway shuts down the pathway

Autotroph

An organism that makes its own food ex-bacteria, algae, plants

Heterotroph

An organism that cannot make its own food. ex- humans

Respiration of glucose

glycolysis, krebs cycle, electron transport chain

Glycolysis

the breakdown of glucose by enzymes, releasing energy and pyruvic acid.

releases 4 ATP total

Pyruvate

Organic compound with a backbone of three carbon atoms. Two molecules form as end products of glycolysis

1 CO2, 1 NADH, 1 acetyle CoA, 1 ATP for each pyruvate2

Krebs cycle

produces molecules that carry energy to the second part of cellular respiration for every Aceyle CoA entering(2) __releases-(2CO2, 3 NAD+ to 3 NADH, 1 FAD to FADH_2)

One Glucose molecule oxidizes to

6CO_2, 4ATP, 10 NADH, 2 FADH_2

Electron Transport Chain (ETC)

series of electron carrier proteins that shuttle high-energy electrons during ATP-generating reactions

Chemiosmosis

A process for synthesizing ATP using the energy of an electrochemical gradient and the ATP synthase enzyme.

Energy yield of respiration

32 ATP per glucose for bacteria

30 ATP per glucose for eukaryotes

anerobic respiration

Respiration that does not require oxygen

Fermentation

Process by which cells release energy in the absence of oxygen

Catabolism of proteins

Amino acids undergo deamination to remove the amino group

Remainder of the amino acid is converted to a molecule that enters glycolysis or the Krebs cycle

Catabolism of fats

Fats are broken down to fatty acids and glycerol

Photosynthesis

-Conversion of light energy from the sun into chemical energy.

-opposite of respiration in terms of products and reactants

-occurs in chloroplast

light dependent

-requires light

-1/2 parts of photosynthesis

-makes ATP + NADP+ --> NADPH

-produces O_2

-in thylokoid membrane

light independent

-doesn't require light

-in stroma

-uses ATP+ NADPH to synthesis organic molecules from CO_2

The shorter the wavelength, the ________ the energy

higher

The longer the wavelength the _________ the energy.

lower

Photoelectric effect

light energy can remove electrons from some molecules

Chlorophylla

main photosynthetic pigment in plants, blue and red lights

-converts light energy to chemical energy

Photosystems

light-collecting units of the chloroplast

an antenna complex

gathers photons and feed the captured light and energy to the reaction center

Reaction center

The chlorophyll a molecule and the electron acceptor in a photosystem; they trigger the light reactions of photosynthesis. The chlorophyll donates an electron, excited by light energy, to the primary electron acceptor, which passes an electron to an electron transport chain.

photosytems I and II

noncylic photophosphorylation

-generates NADPH + ATP

-building organic molecules requires more energy than that

cylic phosphorylation

-allows cells to produce additional ATP

Light Independent-The Calvin cycle

Stage of photosynthesis that forms glucose

Carbon Fixtation-Calvin Cycle

RuBP +CO_2 --> 2PGA

Reduction-Calvin Cycle

PGA is reduced to G3P

Regeneration

G3P regenerates to RuBP

- 3 turns have enough carbon to produce a new G3P

- 6 turns have enough carbon to have 1 glucose

Photorespiration

A metabolic pathway that consumes oxygen, releases carbon dioxide, generates no ATP, and decreases photosynthetic output; generally occurs on hot, dry, bright days, when stomata close and the oxygen concentration in the leaf exceeds that of carbon dioxide.

C4 pathway

a carbon-fixing process in which carbon dioxide is bound to a compound to form a four-carbon intermediate

The CAM pathway

a water-conserving, carbon-fixing process; CAM plants take in carbon at night and fix it into various organic compounds and release it during the day

diagram of chloroplast

1st experiment for DNA question

1928

-Griffith

-discovered transformation(transfer of genetics between cells)

-he infected mice with diseases

2nd Expirement of DNA question

15 years later

- Avery, Maclead, McCarthy

-transofrmations includes DNA transfer between cells

3rd experiment of DNA

-The Hersey- Chase

- 8 years later

- DNA is the genetic makeup of a cell

- viruses that infected bacteria

Chargoff's Rule

-A=T

-G=C

- A+G=T+C

Maurice Wilkins and Rosalind Franklin

-X-ray diffraction studies to identify 3-D structures

-DNA is helical

-DNA diameter- 2nm, makes up every 3.4 n, turn

Watson and Crick

Developed the double helix model of DNA.

G forms ___ hydrogen bonds with C

three

A forms __ hydrogen bonds with T

Two

Conservative model

two parental strands reassociate after acting as templates for new strands thus restoring the parental double helix

semi-conservative replication

1 strand of parent molecules remains intact

disperse- DNA

parts of parental molecules are dispersed throughout

The Meselson-Stahl experiment

Used isotope of nitrogen to change the weight of DNA N15 & N14, demonstrated that the semi-conservative model is the best description of replication.

Leading strand

DNA is synthesized continuously

lagging strand

DNA is synthesized discontinuously

ligase

seals the "nick" in DNA backbone

Okazaki fragments

Short fragments of DNA that are a result of the synthesis of the lagging strand during DNA replication.

sliding B clamp

holds DNA pol (I) to the DNA as it moves along the strand

clamp loader

loads B clamp onto SNA template strand

DNA gyrase

relieves torsional strain

DNA pol (I)

replaces RNA primer with DNA nucleotides

RNA primer

short RNA segment needed to start DNA replication

single stranded DNA binding proteins

coats strands to keep them apart

DNA pol (II)

synthesizes fragments of DNA

Primase

unwinds and synthesizes primer

Helicase

uses ATP to unwind DNA