Stage 1:GLYCOLYSIS

Cellular Respiration

Glycolysis = “sugar splitting”1o reactions that occur in the cytosol

Each step is catalyzed by a specific enzymeOVERALL: Glucose (__C) two pyruvate (__C

each)

Overview of Glycolysis

YIKES!We will breakeach step down,and then summarizethe main points.

Glycolysis in Detail

ATP _____________glucose to glucose 6-phosphate

Glucose 6-phosphate (G6P): _____________________________________________________________________.

MAIN REACTANT(S): ________________ATP INVOLVED (+ or -): ______________________PRODUCTS: _________________

Step 1:

G6P is rearranged to fructose 6-phosphate (F6P)

Fructose 6-phosphate: __________________________________________________________. Carbon 1 becomes

________________ from the ring structure.

MAIN REACTANT(S):___________________ATP INVOLVED (+ or -):______________________PRODUCT(S):____________________________

Step 2:

ATP _____________F6P to fructose 1,6-bisphosphate

F 1, 6-BP: ______________________________________________________________________________________Importance?:___________________________________

MAIN REACTANT(S): ______________________ATP INVOLVED (+ or -): __________________________PRODUCTS: _________________________

Step 3:

4) F 1,6-BP split into DHAP and G3P5) DHAP immediately converted into G3P by an isomerase

enzyme. Therefore, ______ molecules of ______ formed.Importance?:___________________________________________.

MAIN REACTANT(S): ______________________________“INTERMEDIATE REACTANT(S): ______________________________________________________________________ATP INVOLVED (+ or -): _____________________________PRODUCTS: ___________________________________________

Steps 4&5 - cleavage

____ ATP molecules are used in the first 5 steps of glycolysis. One is used in step ____ and one is used in step ____. In both of these reactions, _____________ groups are added to the initial _______________ molecule. This prepares the molecule for ___________.

In step ____, ____________________ is split into __________________________________.

The ____________________ enzyme immediately converts _____________ into _________________, resulting in two molecules of _________________.

There are now ____ G3P molecules for each __________ molecule entering glycolysis.

Let’s review steps 1-5...

STEPS 6-10 HAPPEN EXACTLY THE SAME WAY FOR EACH OF THE __________ MOLECULES.

“DOUBLING” THE REACTION...

A Dehydrogenaseenzyme *catalyzes two sequential reactions:1) NAD+ + 2e- + 1P

NADH2) Adds Pi from cytosol

to G3P.

Step 6:

Regina Bailey, http://biology.about.com/od/cellularprocesses/a/aa082704a.htm

For each Glucose Molecule:

MAIN REACTANT(S):________________________________________ATP INVOLVED (+ or -): :_____________Energy-Harvesting Product(s):___________________________________PRODUCT(S):_______________________________________________

ATP molecules are produced by substrate-level phosphorylation (one for each ____________molecule)

1,3-bisphosphoglycerate (BPG)is converted into 3-phosphoglyerate(3PG)What happened? ____________________________________________.

Step 7: ATP is FINALLY PRODUCED!

MAIN REACTANT(S):_________________ATP INVOLVED (+ or -):_____________Energy-Harvesting Product(s):_____________________________PRODUCT(S):_______________________________________________

Rearrangement of the phosphate group from C3 to C2MAIN REACTANT(S):_________________ATP INVOLVED (+ or -):_____________Energy-Harvesting

Product(s):_____________________________PRODUCT(S):_________________________________________

______

Step 8:

2PG is converted to PEP by removal of water moleculeMAIN REACTANT(S):_________________ATP INVOLVED (+ or -):_____________Energy-Harvesting

Product(s):_____________________________PRODUCT(S):___________________________________________

____

Step 9:

Two ATP molecules are formed by substrate-level phosphorylation.

PEP is converted to pyruvate

MAIN REACTANT(S):_________________ATP INVOLVED (+ or -):_____________Energy-Harvesting Product(s):_____________________________PRODUCT(S):_____________________________________________

Step 10:

ENERGY YIELD:____ ATP USED____ ATP PRODUCED____ NADH PRODUCED----------------------------net:____ ATP PRODUCED____ NADH PRODUCED

... OVERALL...

Note: ATP may be used immediatelyby the cell. NADH will be furtherprocessed to make more ATP.

For each mole of glucose produced:

Energy Conversion Efficiency of Glycolysis

Glycolysis transfers only about 2.2% of the free energy available in1 mol of glucose to ATP.

Majority of energy is still trapped in the two ____________________________ molecules and two _____________ molecules.

Only 2.2% conversion efficiency?!

Glycolysis can be aerobic or anaerobicThe first cells probably used this process to

harness energy, and today, the simplest organisms continue to use it for all their energy needs.

YIELD: ____ ATP molecules for every ____ glucose.

This may be enough energy for the needs of some _________________ organisms, but it is not enough for _________________ organisms.

All organisms carry out glycolysis.

Glycolysis and Life...

Don’t spend a lot of time studying the ‘little things.’

You should look over the whole process, and identify what is important.What are some important steps/processes?INITIAL REACTANTS, ENERGY USED,

ENERGY EXPENDED, REARRANGEMENTS OF MOLECULES, NUMBER OF MOLECULES INVOLVED.

You do not need to memorize the names of the intermediate molecules.

Glycolysis is only the beginning of cellular respiration...

Read pg 99-100Section: “Mitochondria” Answer the following questions:1) The process that produces ATP in mitochondria cannot proceed without

______________________. 2) What are the three stages of cellular respiration that occur within

mitochondria?3) Only _________________ contain mitochondria.4) Where do prokaryotic cells carry out cellular respiration? Why?5) A double membrane is referred to as an ______________. Where else have you

seen this term?6) The folds of mitochondria’s inner membrane are called ______________. It

contains many _________________ and ___________________ imbedded in its _______________________ that participate in the reactions of respiration.

7) The mitochondrial matrix is a _____________________ liquid that fills the ______________________ space of a mitochondrion.

8) A fluid-filled ___________________________ lies between the inner and outer membrane.

9) What is the endosymbiosis hypothesis? What component of mitochondria helped strengthen this theory?

WORK ON THE GLYCOLYSIS HANDOUT. FINISH IT FOR TOMORROW.

Classwork/Homework