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 carbohydrateslipids 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 SystemChew 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

and

TAKES AWAY waste products like CO2.

cell

capillary

Here are the detailed stepsof cellular respiration.Notice the reactants inblue and the products in red.

Where does this take place?

cytoplasm and mitochondrion!

Two parts of cellular respiration:

1. glycolysis

2. aerobic respirationKrebs cycleelectron transport chain

Where does the first step, glycolysis, happen?

In the cytoplasm!

Eukaryotic Prokaryote

http://1.bp.blogspot.com/_y5Bs1CDjkq8/SNKojZ9nUoI/AAAAAAAAAFk/2vLLR_nxXgk/s400/plant_cell.jpg

http://img.search.com/thumb/9/99/Prokaryote_cell_diagram.svg/400px-Prokaryote_cell_diagram.svg.png

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

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 matrixmakes 2CO2, 1 ATP, 3 NADH, 1 FADH2

Aerobic Respiration

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 ChainLast step of aerobic respirationHappens 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!!!

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 RespirationIf oxygen is not available, regenerates NAD+ for glycolysisoccurs in cytoplasm2 types of fermentation:

lactic acid fermentation (animals)pyruvate to lactic acidstrenuous exercise = sore muscles!

alcohol fermentation (yeast, bacteria)yeast and some bacteriapyruvate to ethyl alcohol