Chapter 9 Cell Respiration

How much energy is in food? One gram of _______ “burned” (oxidized) in presence of _______ = 3811 calories of heat energy A _______ is the amount of _______ needed to raise the temperature of one gram of water one degree Celsius. Kilocalorie on food labels (1 Calorie = 1000 calories) When cells “burn” glucose, they release the _______ contained within its _______ bonds. One gram of glucose when oxidized aerobically = 3811 calories

Oxygen or not? Anaerobic: “not in air” Does not require _______ Glycolysis and fermentation Aerobic pathways in cell respiration need _______ to release _______ from food. Krebs cycle and ETC

Overview of Cell Respiration Cellular respiration is the process that releases _______ by breaking down _______ in the presence of _______. 6O2 + C6H12O6  6CO2 + 6H2O + Energy oxygen + glucose  carbon dioxide + water + energy Respiration Overview (3:50)

Study diagram on page 222.

The MIGHTY Mitochondrion

Glycolysis Process in which one molecule of _______ is broken in half, producing two molecules of ________ _______ (pyruvate) Energy input of ___ _____; ___ _____ produced; net gain of ___ _____. 2 ATP 2 ADP 4 ADP 4 ATP Two advantages: speed and does not require oxygen. Cells can produce thousands of ATP molecules in just a few milliseconds. Can provide chemical energy to cell without oxygen. When a cell generates large amounts of energy from ATP, it runs into a problem. In just a few seconds, all of the NAD+ is filled with electrons and the cell cannot keep glycolysis going, thus stopping ATP production. 2NAD+ 2 Pyruvic acid 2

Glycolysis 2NAD+ Overview of Glycolysis (3:00) Two high-energy _______ and ____ picked up by NAD+ to make _______ Energy in NADH carried to _____ No _______ needed and high _______ are the advantages. It’s a form of _____ production in O2-deprived cells (muscle) and red blood cells (no mitochondria) 2 ATP 2 ADP 4 ADP 4 ATP 2NAD+ 2 2 Pyruvic acid Overview of Glycolysis (3:00)

Fermentation If there is no _______ present, cell will go through _____________ Cells convert _______ to NAD+ by passing high energy _______ back to _________, allowing glycolysis to continue producing a steady supply of _____. __________ discovered it’s carried out by microbes

Alcoholic Fermentation Forms _____________ and _____ as wastes. Occurs mainly in _______ and a few other microorganisms Causes bread dough to _______ When yeast in dough run out of _______, they begin to ferment, giving off bubbles of ______. Small amount of alcohol evaporates. Process explained in 1897 by German chemist Eduard Buchner – The birth of biochemistry!!! C6H12O6 + zymase  2C2H5OH + 2CO2

Lactic Acid Fermentation Regenerates NAD+ so _______ can continue. Produced during vigorous exercise in _______ Rapid production of ATP Lactic acid (lactate) is a _______ product Buildup of lactic acid in _____________ causes a painful, burning sensation, but only temporarily Broken down into ____ and _____ by liver Moves the metabolic burden from ___________ to ___________

Lactic Acid Fermentation Metabolism of Lactic Acid – The Cori Cycle

Lactic Acid Fermentation Cheese, yogurt, sour cream, pickles, and sauerkraut are all produced using lactic acid fermentation.

Review The first step of cellular respiration is… Where does glycolysis occur? What occurs if there no oxygen present after glycolysis?

Review What are the two types of fermentation? This type of fermentation occurs in muscle cells: ________________ Two types of phosphorylation in mitochondrion?

Glycolysis (review) Process in which one molecule of glucose is broken in half, producing two molecules of pyruvic acid (pyruvate) Energy input of 2 ATP 2 ATP 2 ADP 4 ADP 4 ATP Two advantages: speed and does not require oxygen. Cells can produce thousands of ATP molecules in just a few milliseconds. Can provide chemical energy to cell without oxygen. One molecule glucose makes 2 molecules of pyruvate. 2NAD+ 2 Pyruvic acid 2

Krebs Cycle During the Krebs cycle, _________ is broken down into CO2 in a series of ________-extracting reactions. Occurs in the _______ of mitochondrion. First described by ______ _________ (1937) aka: The Citric Acid Cycle

Krebs Cycle Begins when __________ enters. One carbon from pyruvate becomes a part of _____ and is released from the cell. At the same time, 2 _______ are combined with 1 H+ ion changing NAD+ into _____. Next, _________ A joins the remaining 2 carbon molecules from pyruvate to form ________-CoA. Acetyl-CoA adds its two- carbon acetyl group to a 4-carbon compound (oxaloacetate) producing ________ acid (citrate).

Krebs Cycle _______ is broken down into a 5-carbon compound (alpha-ketoglutarate) and more _____ is released. Again, 2 electrons and 1 H+ ion convert NAD+ to NADH. Then, another carbon atom leaves in ____ as a waste product, leaving the 4-carbon compound _______ acid (malate).

Krebs Cycle Krebs Overview (1:55) Following that, NAD+ picks up 2 __________ and an ____ ion and becomes __________. Also, ADP is converted into _____. Next, ______ picks up 2 __________ and 2 _____ ions and becomes __________ Finally, another ______ picks up 2 __________ and an _____ ion and oxaloacetate moves on to start the cycle again. Krebs Overview (1:55)

Where do the products of the Krebs Cycle go? CO2 released into the _______ ATP used for cell activities NADH and FADH2 used to generate large amounts of ATP in the ______.

Review Where does the Krebs cycle take place? Number of ATPs generated by Krebs for each molecule of glucose? Two electron carriers generated by Krebs? Waste product of Krebs?

Electron Transport Chain The ETC uses high-energy _______ from the _______ _______ to convert 32 ADPs to 32 ATPs. Series of carrier proteins located in inner ____________ of ______________. So, O2 is essential for getting rid of low-energy electrons and hydrogen ions (wastes of cell respiration) ADP

________ serves as the final electron acceptor of the ETC. High-energy _______ from NADH and FADH2 are passed from one carrier to the next. At the end, an enzyme combines these electrons with H+ ions and oxygen to form _______. ________ serves as the final electron acceptor of the ETC. ADP

Electron Transport Chain Each time 2 ________ travel down the ETC, their energy is used to pump _____ ions across the membrane from the matrix to the intermembrane space of the ____________. _____ ions build up in the intermembrane space, making it __________ charged and the outside __________ charged. ADP

Electron Transport Chain This imbalance of _______ between the matrix and the intermembrane space causes H+ ions to move through _____ ___________. ATP synthase turns when this happens, converting _____ to _____ Average of 3 ATPs for every pair of _________ ETC Review (2:02) ADP

Review Number of ATPs produced in ETC? Waste product of ETC? Purpose of energetic electrons? Location of ETC in eukaryotes? Prokaryotes? What enables ATP synthase to produce ATP?

So What’s the Point?? The overall goals of the four pathways are: a. Glycolysis: to convert ________into ______ for fermentation or _______ b. Fermentation: to produce ______ to keep _______ going c. Krebs: to produce _______ and _______ for the _____ d. ETC: to produce large amounts of _____ for the cell

How much energy does a single molecule of glucose provide? Glycolysis = 2 ATP Krebs Cycle = 2 ATP ETC = 32 ATP TOTAL = 36 ATP 18 times more ATP produced with _______ Respiration extracts about 38 percent of total _______ of _______. Remaining 62 percent released as ______

What happens when you need a burst of energy? Your body contains enough _____ for only a few seconds of intense activity. When you participate in vigorous ________, after a few seconds your body will begin to produce _____ by _______ _______ fermentation. This type of ATP production will last about 90 _______.

What happens if you need energy for longer than 90 seconds? ________ respiration is the only way to generate a continuing supply of ______. Releases ________ slower than fermentation. Which means athletes need to train and pace themselves. Body stores energy in muscle and other tissues in the form of the carb ___________, which can supply energy for 15-20 mins. After that, body breaks down stored molecules, like ________ & _______ for energy. This is why running, swimming, etc. are so good for weight control. Of the carb glycogen

Comparing Photosynthesis and Respiration _______ flow takes place in ________ directions Photosynthesis ________energy; respiration ___________ energy Cell respiration occurs in all eukaryotes and nearly all prokaryotes. Photosynthesis occurs only in plants, algae, and some bacteria. What happens to O2 and CO2 in plant cell? Energy flows take place in opposite directions. Photosynthesis “deposits” energy, respiration “withdraws” energy. Photosynthesis removes CO2 and respiration puts its back. Respiration uses the oxygen that photosynthesis releases.