Bio 110- Ch 6 Cellular Respiration

Heterotroph

"other feeders" use organic molecules as fuel, consumers

Citric Acid Cycle

(1) Acetic Acid joins a 4-C acceptor molecule ---> 6-C (citric acid) (2) Two CO2 exit as waste. Along the way, the citric acid cycle harvests energy from the fuel (3) Energy is used to form 1 ATP directly (4) Energy from 3 NADH (5) Energy from 1 FADH2. THE WHOLE CYCLE REPEATS TWICE. Net output= 2 ATP, 6 NADH, 2 FADH2

Citric acid cycle prep steps

(1) Start with Pyruvic Acid (CO2+ 2-C) then Pyruvic Acid loses the CO2 to make Acetic Acid (2) Oxidation of the fuel generates NADH (3) Finally, each acetic acid is attached to a molecule called coenzyme A (CoA) to form acetyl CoA. The CoA escorts the acetic acid into the 1st reaction of the citric acid cycle. The CoA is stripped and recycled.

The net gain of ATP for each glucose molecule that enters glycolysis, in the absence of oxygen, is approximately __________.

2 ATPs

Some members of _____ thrive in anaerobic environments. Why is this so?

Archea because ancient prokaryotic organisms lived long before significant levels of O2 were present in Earth's atmosphere.

Photosynthesis:

A chemical process that uses light energy from the sun to build organic molecules. Humans and other animals depend on the food that plants make by photosynthesis.

Archeans:

Archeans are all single-celled organisms. Some thrive in anaerobic environments like the oxygen-free mud in marshes or petroleum deposits deep underground. Other organisms besides archeans can thrive in oxygen-free environments as well. Yeast and some bacteria are examples.

Lactic Acid

A waste product formed from the addition of electrons to pyruvic acid. Lactic acid is eventually transported to the liver, where liver cells convert it back to pyruvic acid.

FADH2

Also a coenzyme and an electron carrier

The correct general equation for cellular respiration?

C6H12O6 + 6 O2 → 6 CO2 + 6 H2O + ATP energy

The citric acid cycle breaks down _____, releasing _____ and forming some _____.

Carbon molecules...carbon dioxide...ATP

"C6H12O6 + 6 O2 → 6 CO2 + 6 H2O + ATP energy" explained in words

Cellular respiration extracts energy from glucose (C6H12O6) to produce smaller energy packets (ATP).

Redox Reactions

Chemical reactions that transfer electrons from one substance to another

In the electron transport chain, electrons move from one _____ to another, eventually reaching _____. The released energy is used to make _____.

Electron carrier...oxygen...ATPs

What occurs in the ATP synthase machine?

Electrons are removed from food and carried by the electron transport chain to ATP synthase enzymes.

Most of the ATP production during cellular respiration occurs __________.

From activity of the ATP synthase machine.

Reduction

GER (gain of electron), H added

In glycolysis, _____ is split into two molecules of _____. The released energy is stored in _____ and the electron carrier _____.

Glucose...pyruvic acid...ATP...NADH

Which of the following processes takes place in the cytosol of a eukaryotic cell?

Glycolysis

What is glycolysis?

Glycolysis is the breakdown of glucose into two molecules of pyruvic acid, takes place in the cytosol, outside the mitochondria. This process splits glucose in half and produces 2 ATPs for each glucose.

3 Metabolic stages of cellular respiration

Glycolysis, citric acid cycle, and electron transport chain

Fermentation in microorganisms

If kept in an anaerobic environment, microscopic fungi (such as yeast) are forced to ferment sugars and other foods to stay alive. When yeast ferment, they produce ethyl alcohol as a waste instead of lactic acid. This alcoholic fermentation also releases CO2.

Glycolysis

In the cell cytoplasm, the splitting of sugar (glucose). (1) 6-C glucose molecule is split and makes 2 3-C molecules (pyruvic acid) (2) Requires 2 ATP (uses Energy), the 2 3-C molecules donate electrons to NAD+ to make 2 NADH *used 2 ATP to make 2 NADH* (3) Also, made 4 ATP but used 2 (net 2 ATP)

Electron Transport Chain

Inner membrane of Mitochondria (1) NADH and FADH2 become NAD+ and FAD after they both transfer their electrons into the electron transport chain (2) The ETC uses this energy supply to pump H+ across the inner mitochondrial membrane (3) Oxygen pulls electrons down the ETC (4) The H+ concentrated on one side of the membrane rushes back "downhill" through the ATP Synthase, just as H2O turns the turbines in a dam (5) The rotation from the ATP Synthase activates various parts of the synthase molecule that attach phosphate groups to ADP molecules to generate ATP.

Oxidation

LEO (loss of electron), H removed

Slow twitch muscles

Long time use, use O2, calf muscle, marathon runners

In what organelle would you find acetyl CoA formation, the citric acid cycle, and the electron transport chain?

Mitochondrion (all of the steps of cellular respiration except glycolysis take place in the mitochondrion)

Electron carrier molecules work by coupling electron transfer between electron donors and acceptors (such as ____ and ____) with the transfer of _____ ions across the inner _____ membrane.

NADH and O2...H+...mitochondrial

Fast twitch muscles

No O2, contract quickly, sprinter

Autotroph

Organisms are "self feeders" all plants, get energy from light, producers

Aerobic metabolism always requires _____.

Oxygen

Cyanide

Poison cyanide produces deadly effect by binding to one of the protein complexes in the ETC. When bonded, Cyanide blocks the passage of electrons to oxygen. As a result, no H+ gradient is generated, and no ATP is made. Cells stop working and the organism dies.

NADH

Reduced form of NAD+ "co enzyme", it is an electron carrier, moves 1 molecule to another

What is cytosol?

The cytosol is the fluid that is inside the cell but outside the organelles.

The electron transport chain is a series of electron carrier molecules. Where are these molecules located in eukaryotic cells?

The inner membrane of the mitochondria

Fermentation in human muscle cells

The recycling of NAD+ can't occur under anaerobic conditions because there is no O2 to accept the electrons. Instead, NADH disposes of electrons by adding them to the pyruvic acid produced by glycolysis. This restores NAD+ and keeps glycolysis working.

Describe the citric acid cycle

This process produces some ATP and carbon dioxide in the mitochondrion.

Describe the electron transport chain

This process uses energy captured from electrons flowing to oxygen to produce most of the ATPs in cellular respiration.

What are the end products of cellular respiration?

Water, carbon dioxide, and energy are the end products of cellular respiration.

The chemical ingredients needed for photosynthesis are _____ and _____.

carbon dioxide ... water

The correct sequence of steps as energy is extracted from glucose during cellular respiration:

glycolysis → acetyl CoA → citric acid cycle → electron transport chain **Glycolysis produces pyruvic acid, which enters the mitochondrion. There, it is converted to acetyl CoA, which enters the citric acid cycle. Electron carriers bring electrons from the first three steps to the electron transport chain, and ATP is made.**