February 14, 2014

Pick up the handout and schedulefrom the front

1st Law of ThermodynamicsThe energy of the universe isconstant. Energy can be transformed & transferred, but it cannot be created or destroyed.

2nd Law of ThermodynamicsEvery energy transfer ortransformation makes the universe more disordered. In other words,every energy transfer or transformation increases theentropy of the universe

Based on free energy changes, reactions can be classified as exergonic (energy outward) or endergonic (energy inward). An exergonic reaction proceeds with a net release of free energy. They occur spontaneously. An endergonic reaction is one that absorbs free energy from its surrounds; the energy is stored in the product; they are nonspontaneous.

Energy Transfer

25 kJ

Here is a food pyramid that begins with producers and ends with tertiary consumers. If the producer level contains 25,000 kJ of energy and this pyramid follows the 10% rule, then how much energy gets transmitted to the tertiary consumers?

All of the questions are printed at the back of your handout

42 g/m2

Carbon Flow in a Grassland Ecosystem

How much carbon (g/m2) is released into the atmosphere as a result of the metabolic activity of the herbivores?

ΔG = ΔH – TΔSG = Free EnergyH = EnthalpyS = EntropyT = Temperature in KelvinΔ represents change in value over time

An experiment determined that when a protein unfolds to its denatured (D) state from the original folded (F) state, the change in Enthalpy is ΔH = H(D) – H(F) = 56,000 joules/mol. Also the change in Entropy is ΔS = S(D) – S(F) = 178 joules/mol. At a temperature of 20 C, ⁰calculate the change in Free Energy ΔG, in j/mol, when the protein unfolds from its folded state.

The correct answer is 3,846 joules/mol.ΔG = ΔH – TΔSΔG = (56,000 joules/mol) – 293 K (178 joules /mol)ΔG = 56,000 joules/mol – 52,154 joules/mol = 3,846 joules/mol

A + B + energy → ABThere are many types of biochemical reactions taking place in any living system. Which of the followingbest characterizes the reaction represented above?A) CatabolismB) Oxidation-reductionC) Exergonic reactionD) Endergonic reaction

Energy Transfer

C6H12O6 + 6O2 6CO2 + 6H2O + Energy

becomes oxidized

becomes reduced

6CO2 + 6H20 + energy C6H12O6 + 6O2

C6H12O6 + 6O26CO2 + 6H20 + energy

When you compare the formula for photosynthesis with cellular respiration, which is exergonic, which is endergonic? They are both oxidation/reduction reactions.

6CO2 + 6H20 + energy C6H12O6 + 6O2

C6H12O6 + 6O26CO2 + 6H20 + energy

CELLULAR RESPIRATION- AN OVERVIEW

Where is the energy transfer?

Where is the energy transfer?

A molecule that is phosphorylated:

a.Has an increased chemical reactivity; it is primed to do cellular workb.Has a decreased chemical reactivity; it is less likely to provide energy for cellular workc.Has been oxidized as a result of a redox reaction involving the gain of inorganic phosphated.Has been reduced as a result of a redox reaction involving the loss of an inorganic phosphate

Which of the following statements describes the results of this reaction?

C6H12O6 + 6O2 6CO2 + 6H20 + energy

a. C6H12O6 is oxidized and O2 is reducedb. O2 is oxidized and H20 is reducedc. CO2 is reduced and O2 is oxidizedd. C6H12O6 is reduced and CO2 is oxidized

Starting with one molecule of glucose, the“net” products of glycolysis are:

a.2 NAD+, 2 H+, 2 pyruvate, 2 ATP and 2 H20b.2 NADH, 2 H+, 2 pyruvate, 2 ATP, and 2 H20c.2 FADH2, 2 pyruvate, 4 ATP and 2 H20d.6 CO2, 6 H20, 2 ATP and 2 pyruvate

Where is the energy transfer?

Pyruvate(from glycolysis,2 molecules per glucose)

ATP ATP ATP

Glycolysis Oxidationphosphorylation

CitricacidcycleNAD+

NADH+ H+

CO2

CoA

Acetyl CoACoA

CoA

Citricacidcycle

CO22

3 NAD+

+ 3 H+

NADH3

ATP

ADP + Pi

FADH2

FAD

Where is the energy transfer?

Where is the energy transfer?

Where is the energy transfer?

Where is the energy transfer?

Where is the energy transfer?

Where is the energy transfer?

There is “compartmentalization” within themitochondrion. What purpose does it serve?

How is a concentration gradient important inthe process shown here?

What is the significance of the inner membranebeing folded?

Add it all up-

This is probably26-28 ATP

This number isProbably lower

The oxygen consumed during cellular respiration is involved directly in which process or event?a.Glycolysisb.Accepting electrons at the end of the end of the electron transport chainc.The citric acid cycled.The oxidation of pyruvate to acetyl CoA

Organic molecules besides carbohydrates can transfer energy

Which process in eukaryotic cells will proceed normally whether O2 is present or not and therefore probably evolved first?a.Electron transportb.Glycolysisc.The citric acid cycled.Oxidative phosphorylation

You have a friend who lost 7 kg (about 15 pounds) of fat on a low carb diet. How did the fat leave her body?

a. It was released as carbon dioxide and water

b. Chemical energy was converted to heat and released

c. It was converted to ATP, which weighs less than fat

d. It was converted to urine and eliminated from the body

Photosynthesis!!!

Relate the structure to the function-

We have compartmentalization again

Lots of surface area

Relate structure and function-

-At the organ level

-At the tissue level

-At the cellular level

-At the molecular level

Photosynthesis- An Overview

Where is the energy transfer?

Where is the energy transfer?

Where is the energy transfer?

Where is the energy transfer?

C3 Plants

Where is the energy transfer?

Use these terms to summarize the Calvin Cycle.

Carbon dioxide (CO2)Ribulose biphosphate (RuBP)Rubisco 3-phosphoglycerateATPNADPHGlyceraldehyde-3-phosphate (G3P)Glucose

In the Calvin Cycle, CO2 is attached to a molecule of RUBP. This is catalyzed by the enzyme rubisco. The six carbon product splits, forming two molecules of 3-phosphoglycerate. 3-phosphyglycerate receives a phosphate from ATP and electrons from NADPH forming a molecule of G3P. Two molecules of G3P can combine to form a molecule of glucose.

Where is the energy transfer?

Photosynthetic Adaptations

Alternate mode of carbonfixation that forms a 4-carbon compound as its first product.A way to cut down on photorespiration.Sugarcane, corn, members ofthe grass family (at least 1000 plants)

CAM PhotosynthesisEvolved in succulent plants, many cacti, pineapples &other plants. Open stomata during night, close during day

Compare and contrast the energy transfer in mitochondria & chloroplasts

Energy Flow in a Hardwood ForestWhat percentage of the biomass in the forest community is tied up in theGrass layer which has a question mark?

The End

The

End