Cellular Respiration Ch. 8.3

Every living organism needs ENERGY! To move things through the cell membrane. To move organelles in cells. To move muscle cells. To make nerve cells allow you to think!

Food provides Matter. Molecules of food (matter) build new parts of an organism: proteins carbohydrates lipids nucleic acids http://www.320x480.org/animals/red-eyed-tree-frog/

Food also provides Energy! The chemical bonds of glucose store ENERGY for other cell processes.

How do you get the energy out of food? Through a series of chemical reactions called cellular respiration.

C6H12O6 + O2  CO2 + H2O + ENERGY Does it look familiar? Look at it backwards: Energy + CO2 + H2O ---- C6H12O6 + O2 What is this?

Photosynthesis makes glucose to store energy. (anabolic pathway) Cellular Respiration breaks down glucose to get the energy back out. (catabolic pathway)

Who needs cellular respiration?

To get energy from food: Step 1: Digestion in the GI tract. Step 2: Cellular Respiration

Digestive System Chew food to break it into pieces. Stomach acid and enzymes break it down more. Food molecules are absorbed into blood and transported to cells.

Blood takes nutrients like glucose TO cells capillary Blood takes nutrients like glucose TO cells and TAKES AWAY waste products like CO2. cell

Here are the detailed steps of cellular respiration. Notice the reactants in blue and the products in red. Where does this take place? cytoplasm and mitochondrion!

Two parts of cellular respiration: 1. glycolysis 2. aerobic respiration Krebs cycle electron transport chain

Where does the first step, glycolysis, happen? In the cytoplasm!

Eukaryotic Prokaryote http://img.search.com/thumb/9/99/Prokaryote_cell_diagram.svg/400px-Prokaryote_cell_diagram.svg.png http://1.bp.blogspot.com/_y5Bs1CDjkq8/SNKojZ9nUoI/AAAAAAAAAFk/2vLLR_nxXgk/s400/plant_cell.jpg

When glucose gets into a cell, GLYCOLYSIS breaks it down. occurs in the cytoplasm. chemical reactions use enzymes anaerobic reaction = No Oxygen needed! net yield 2 pyruvate from 1 glucose molecule makes 4 ATP, but uses 2 ATP so it Releases only 2 ATP! http://www.science.smith.edu/departments/Biology/Bio231/glycolysis.html http://www.johnkyrk.com/glycolysis.html

CO2 H2O

Where does the aerobic step of aerobic respiration, happen? In the “powerhouse of the cell” the MITOCHONDRION!

Overview of cellular respiration mitochondrion Cellular Respiration overview, focus on ETC

Aerobic Respiration Pyruvate from glycolysis is converted by enzymes to acetyl CoA which enters the mitochondrial matrix. Krebs cycle (Citric Acid cycle): Chemical reactions use enzymes. in mitochondrial matrix makes 2CO2, 1 ATP, 3 NADH, 1 FADH2

http://content. answcdn http://content.answcdn.com/main/content/img/oxford/Oxford_Chemistry/0192801015.krebs-cycle.1.jpg

http://media.wiley.com/Lux/45/8545.nfg001.jpg

Electron Transport Chain Last step of aerobic respiration Happens across inner mitochondrial membrane. High energy electrons and H+ from NADH and FADH2 in Krebs convert ADP to ATP through chemiosmosis. Overall, makes 34 ATP from one glucose molecule!!! Electron Transport Chain

http://classes. midlandstech http://classes.midlandstech.edu/carterp/courses/bio225/chap05/Aerobic_cellular_respiration.jpg

YOUTUBE Electron Tranport Chain overview ETC

Electron Transport Chain http://biosciencesarchive.uga.edu/1996/spring_96/bio_104/notes/may_29.html

Anaerobic Respiration If oxygen is not available, regenerates NAD+ for glycolysis occurs in cytoplasm 2 types of fermentation: lactic acid fermentation (animals) pyruvate to lactic acid strenuous exercise = sore muscles! alcohol fermentation (yeast, bacteria) yeast and some bacteria pyruvate to ethyl alcohol Anaerobic Respiration