CELLULAR RESPIRATION Chemical Pathways

___________ use energy from sunlight or chemicals to make their own food AUTOTROPHS In the last section green plants used ________________ to trap energy from __________ and make ______________ sunlight food (glucose) PHOTOSYNTHESIS

In this section, we will learn how this glucose is ____________ by organisms and the _______ is stored as _______ in a process called ___________________ What kind of organisms do this? energy broken down ATP CELLULAR RESPIRATION

________ (Including _______) ALL LIVING THINGS NEED ENERGY! What kind of organisms do this? plantsfungibacteria ______ animals humans

We get the energy the plants stored as glucose by _____________ directly or eating the _________ that ate the plants. How do we get the sugar from the plants? Image from: REMEMBER! _______________ get their energy by eating other organisms. HETEROTROPHS eating plants animals

We get our energy from the __________ plants made during _______________ when we eat plants or eat animals that ate the plants. GLUCOSE In this section we will learn how ______________ get their energy by consuming other organisms. Image from: HETEROTROPHS PHOTOSYNTHESIS

REMEMBER CELL BIO??

Area with gel-like material inside cell membrane surrounding mitochondria = ______________________ Power plant of cell that burns glucose and stores the energy as ATP = _______________ mitochondria CYTOPLASM Image from:

MITOCHONDRIA = cell power plant Surrounded by ___________ membrane Outer membrane & Inner membrane (called _______________ ) Space between inner membrane & outer membrane = ____________________ Space inside cristae folds = _________________ INTERMEMBRANE SPACE DOUBLE MATRIX CRISTAE

Cellular Respiration Is an aerobic process—requires oxygen Takes place in the mitochondria

Heterotrophs use ________________ to release energy from FOOD (glucose) to make _____ Image by Riedell Image from: ATP CELLULAR RESPIRATION

CELLULAR RESPIRATION happens __________ in ________________. If all the energy was released in one step… most would be lost as ____________________! slowly many steps light and heat

PHOTOSYNTHESIS ___________ + _________ + ___________ → _______________ + __________ 6 CO 2 6 H 2 OC 6 H 12 O 6 6O 2 _____________ + _________ → ________ + __________ + __________ ______________________________________________________________ CELLULAR RESPIRATION C 6 H 12 O 6 6O 2 6 CO 2 6 H 2 O The two equations are exact opposites!

Cellular Respiration Mitochondria cannot directly produce ATP First…foods are broken down into small products (GLUCOSE) Glucose is broken down by a process known as glycolysis →

See glycolysis movie The first step in cellular respiration = __________________ happens in the ________________ outside the mitochondria does not need oxygen (anaerobic) Splits glucose into two three-carbon molecules Net Gain: 2 ATP molecules GLYCOLYSIS CYTOPLASM

Glycolysis (GLYKOS = ________ LYSIS= ___________ ) Glycolysis ____________________________ BUT it needs some ____________to get it started. What molecule do you think is going to supply the energy do this? split apart DOES NOT REQUIRE OXYGEN ATP sweet ENERGY

________ ↓ ___________ → → _____________ ↓ ____________________ + _______________ GLUCOSE2 PYRUVIC ACID PUT IN ________ and GET BACK __________ Net gain of ________ and __________ 2 ATP’s 4 ATP’s GLYCOLYSIS 2 ATP’s 2 NADH ATP ATP NADH

Glycolysis is needed for cellular respiration. –two ATP molecules are used to split glucose –four ATP molecules are produced (NET GAIN OF 2 ATP) –two molecules of NADH produced –two molecules of pyruvate produced

The products of glycolysis enter cellular respiration when oxygen is available. The two, three carbon molecules leaving glycolysis will enter the mitochondria Cellular Respiration occurs in two stages –1. Krebs Cycle –2. Electron Transport Chain

Stage 1: Krebs Cycle Takes place in mitochondrial matrix Breaks down the three-carbon molecules that came from glycolysis makes a small amount of ATP Releases Carbon Dioxide Transfers electron-carrying molecules (NADH & FADH 2 ) to stage 2 (the electron transport chain)

The Krebs cycle is the first main part of cellular respiration. Pyruvate is broken down before the Krebs cycle. –carbon dioxide released –NADH produced –coenzyme A (CoA) bonds to two-carbon molecule

The Krebs cycle produces energy- carrying molecules.

–NADH and FADH 2 are made –intermediate molecule with CoA enters Krebs cycle –citric acid (six-carbon molecule) is formed –citric acid is broken down, carbon dioxide is released, and NADH is made –five-carbon molecule is broken down, carbon dioxide is released, NADH and ATP are made –four-carbon molecule is rearranged

Products of Krebs Cycle Breaking down one molecule of pyruvate: –Carbon Dioxide (3) –ATP (1) –NADH (4) –FADH 2 (1)

Stage 2: Electron Transport Chain Produces a large amount of ATP Takes place in inner membrane of mitochondria Oxygen enters the process ATP produced Water released as a waste product

The electron transport chain is the second main part of cellular respiration. The electron transport chain uses NADH and FADH 2 to make ATP. –high-energy electrons enter electron transport chain –energy is used to transport hydrogen ions across the inner membrane –hydrogen ions flow through a channel in the membrane

Electron Transport Chain

The electron transport chain is the second main part of cellular respiration. –ATP synthase produces ATP –oxygen picks up electrons and hydrogen ions –water is released as a waste product

ATP Production Approximately 38 ATP molecules are produced when one glucose molecule is broken down. –2 from glycolysis –36 from cellular respiration 2 from Krebs Cycle 34 from ETC

Cellular Respiration

6H O 2 6CO 2 6O 2 mitochondrion matrix (area enclosed by inner membrane) inner membrane ATP energy energy from glycolysis and

PYRUVIC ACID MOVES TO NEXT STEP IF THERE IS NO OXYGEN (______________) IF THERE IS OXYGEN (_____________) = ANAEROBIC = AEROBIC

PYRUVIC ACID ___________ OXYGEN 2 kinds of fermentation ___________________ & _____________________ ANAEROBIC Alcoholic Lactic acid WITHOUT

_______ + _____ → __________ + ______ + _____ ALCOHOLIC FERMENTATION PYRUVIC ACID ALCOHOL Happens when yeast makes bread dough rise CO 2 bubbles make _____________ in bread Alcohol _______________ during cooking CO 2 NAD + air spaces evaporates

_______ + _____ → __________ + ______ + _____ ALCOHOLIC FERMENTATION PYRUVIC ACID ALCOHOL Happens when ___________ make _______ or ____________ make ______ CO 2 NAD + yeast beer bacteriawine

_______ + _____ → ______________ + ________ LACTIC ACID FERMENTATION PYRUVIC ACID LACTIC ACID Happens in _____________ during ____________when body can’t get oxygen to tissues fast enough. Lactic acid builds up in muscles causing soreness NAD + exercise muscles

_______ + _____ → ______________ + ________ LACTIC ACID FERMENTATION PYRUVIC ACID LACTIC ACID Happens when bacteria are used to make foods and beverages like: __________________________ NAD yogurt, cheese, buttermilk, & sour cream, pickles, saurkraut, and kimchi

WITHOUT OXYGEN, PYRUVIC ACID ___________ and all the _______ carriers get full. Eventually glycolysis will WHY DO FERMENTATION? WHY NOT JUST KEEP MAKING ATP USING GLYCOLYSIS? builds up NAD +

_______ + _____ → __________ + ______ + _____ FERMENTATION HAPPENS so cells can ____________________ needed to keep glycolysis going PYRUVIC ACID ALCOHOL → CO 2 NAD + REGENERATE the NAD + LACTIC ACID NAD + → You get the NAD + carriers back ______

Flooded Corn Field plants need ______________________ too. If plants seeds are under water 3 days or more, the seeds will die. If a plants roots are under water for 3 days or more, the plants will die. By: Plants do ____________ but photosynthesis oxygen for cellular respiration