6.4-6.6 Flashcards
How much of a person’s daily energy is used on involuntary actions?
75%
What organ needs a lot of energy and burns a quarter of a pound of ATP to sustain itself and the body?
The brain
Kilocalorie, or Calorie, is a unit measured by what?
How much heat is required to raise a kilogram of water one degree celsius.
For the average human, how many kcals of energy are needed?
2200
What helps a person maintain a healthy weight?
Energy intake and expenditure must be close.
What voluntary motion uses the most enrgt (usually)
running.
How does energy expenditure happen?
Through ATP
Walking at 3 mph, you would have to burn off an extra slice of pizza, which is about 475 calories? (3mph walking burns 245 calories per hour)
six miles total
What is a redox (oxidation-reduction) reaction?
The movement of electrons from one molecule to another. The loss of one or more of electrons is oxidation and the gain of one or more electrons is reduction. For this reason, oxidation and reduction are always paired together. An example of this is in cellular respiration.
What acts as the electrons in a products-reactant format equation?
Hydrogen ions (H+ (which is just a proton) and H-)
What is NAD+ and what does it do?
A coenzyme that helps oxidize glucose. As shown by the “+” it can accept an H- ion from glucose. It acts as a “shuttle” for electrons. Its official name is nicotinamide adenine dinucleotide, and is made of vitamin niacin. It actually accepts two hydrogen ions (-), and becomes NADH with an electron and and a proton
What is dehydrogenase?
The molecule used to “strip” hydrogen atoms from other molecules and give them to NAH+.
How are electrons carried from NADH to oxygen? What does this oxygen become?
NADH is the reduced form of NAD+ (the other hydrogen molecule/proton is released). NADH delivers hydrogen atoms to other carrier molecules which bring it to oxygen (which the book describes as 1/2O2, strangely). When the oxygen accepts two electrons, it accepts two hydrogens and becomes water.
What does the electron transport chain consist of? Where is it found?
The electron transport chain consists of all the redox and shuttling reactions talked about above. Ex those between glucose, NAD+, and the carrier molecules. These molecules are found embedded in the inner membrane of mitochondria. The energy released between the carriers is small and controlled enough to make ATP.
What chemical characteristic of the element oxygen accounts for its function in cellular respiration?
Oxygen is extremely electronegative, making it very powerful in pulling electrons down the electron transport chain.
What do redox reactions do in cellular respiration?
Electron transfer from glucose to oxygen. (*Oxygen is very electronegative). Much more controlled than other releases of energy. The glucose molecule becomes oxidized when it becomes CO2, and the water is reduced when it gains H- molecules (see pg. 92).
What are the three stages of cellular respiration?
Glycolysis, citric acid cycle, oxidative phosphorylation.
What is glycolysis (basic definition)?
Happens within the cytosol of the cell. Breaks down glucose into two three-carbon molecules called pyruvate.
What is the citric acid cycle (basic definition)?
Happens within mitochondrial matrix. Takes oxidized (and therefore two-carbon), pyruvate. Breaks down glucose to carbon dioxide. During the first two processes, a small amount of ATP can me made. However, they mostly act to gather electrons for the final stage.
Where does the CO2 you exhale come from?
From the citric acid cycle.
What is oxidative phosphorylation (basic definition)?
Chemiosmosis, a proton transport process, uses electrons to move electrons along the chain in the inner membrane. Most ATP is generated from this part of cellular respiration.
What is FADH2?
Another type of electron carrier like NADH.
What is chemiosmosis?
is the movement of ions across a selectively permeable membrane, down their electrochemical gradient, primarily used in the production of ATP during cellular respiration and photosynthesis. They move from the matrix to the intermembrane space
Where do the electrons come from to help phosphorylate ATP to ADP?
The “downhill fall” of electrons from NADH and FADH2 into the proteins. These proteins release H+ molecules (protons) to matrix?
What couples the electron transport chain to ATP synthesis?
While also sending electrons down the “nrg hill” it send H+ ions to the intermembrane space of the mitochondrial membrane. Creating a concentration gradient of H anions.
Of the three main stages of cellular respiration, which is the only one that uses oxygen?
Oxidative phosphorylation, in which the electron transport chain ultimately transfers electrons to oxygen.
What is chemiosmosis?
The use of the potential energy of the H+ ions to create ATP.
