Chapter 13: How Cells Obtain Energy from Food Flashcards
During respiration, energy is retrieved from the high-energy bonds found in certain organic molecules. In addition to energy, what are the ultimate products of respiration?
CO2 and H20
During photosynthesis, what are the products?
O2 and Sugars
Essentially, what photosynthesis produces are the reactants for cellular respiration.
During photosynthesis, what are the reactants (inputs)?
CO2 and H20
During cellular respiration, what are the reactants (inputs)?
sugars + O2
Remember you need food and oxygen to survive and have energy!
Which groups of organisms undergo photosynthesis?
Plants, Algae, some bacteria
Which groups of organisms undergo cellular respiration?
most living organisms
Energy released during anabolism was acquired from the sun during photosynthesis. True or false?
False. It’s during catabolism.
Energy released during catabolism was acquired from the sun during photosynthesis. True or false?
True
A chemical reaction is defined as spontaneous if there is a net loss of free energy during the reaction process. However, spontaneous reactions do not always occur rapidly. Favorable biological reactions require ______ to selectively speed up reactions and meet demands of the cell.
enzymes
Your body extracts energy from the food you ingest by catalyzing reactions that essentially “burn” the food molecules in a step-wise fashion. What is another way to describe this process?
oxidation
If you weigh yourself on a scale one morning, then eat 4 pounds of food during the day, will you weigh 4 pounds more the next morning?
NO, because only a small portion of the mass of the food will form components of the body. Much of the mass of food is either released as CO2 and H20 that are breathed out into the atmosphere or converted into materials excreted as waste products.
What is the group carried in high-energy linkage for the activated carrier ATP?
Makes sense. You attach a phosphate to the ADP to activate ATP.
phosphate
What is the group carried in high-energy linkage for the activated carrier NADH, NADPH, FADH2?
electrons and hydrogens
What is the group carried in high-energy linkage for the activated carrier ACetyl CoA?
acetyl group
What is the activated carrier for the phosphate?
ATP
What are the activated carriers for the electrons and hydrogens?
Think… I rather sing in the sun…. FA-NA-NA:
FADH2, NADH, NADPH,
Also, remember all of them HAVE hydrogens in them!
What is the activated carrier for the acetyl group?
Acetyl CoA
For delta G < 0….
a) Is the process spontaneous or non-spontaneous?
b) Exergonic or endergonic?
a) spontaneous;
b) exergonic?
For delta G > 0….
a) Is the process spontaneous or non-spontaneous?
b) Exergonic or endergonic?
a) non-spontaneous;
b) endergonic
For delta G = 0….
a) Is the process spontaneous or non-spontaneous?
b) Exergonic or endergonic?
a) Neither. It’s in equilibrium;
b) Neither. It’s in equilibrium;
Catabolism is a energetically ______ reaction.
favorable
Anabolism is a energetically _______ reaction.
unfavorable
What is the cool mnemonic for redox reactions?
LEO the lion says GER!!!
Loss of electrons is ______.
oxidation
Gain of electrons is _______.
reduction
Give an example of a nonspontaneous, endergonic, favorable reaction.
condensation
Give an example of a spontaneous, exergonic, unfavorable reaction.
hydrolysis
A readily available source of energy that cells use to drive reactions is stored in the ______ bond.
phosphoanhydride
A common type of reaction that is needed for ______ is one which two molecules, A and B, are joined together by a _____ bond, to produce A-B in the energetically unfavorable ______ reaction.
biosynthesis; covalent; condensation
NADH, NADPH, and FADH2 are ____ carriers.
activated
NADH, NADPH, and FADH2 carry __ electrons and a ___.
2; H+
Although ATP and NADH are both important activated carrier molecules, ATP Hydrolysis provides the direct molecular energy for most biochemical reactions. Why do the mitochondria also need to generate high levels of NADH?
NADH is an activated carrier molecule used as
- a cofactor for many enzymes that catalyze redox reactions;
- NADH also donates electrons to the electron-transport chian, which is essential for the production of ATP.
When NAD+ receives the high electron energy from the food, it becomes ___.
NADH
When NADH does to the _______, it will donate the electron and then becomes ___ again.
electron transport chain; NAD+
Acetyl coenzyme A (acetyl CaO) is a ____ carrier.
activated
Coenzyme A (CoA) can be converted to _____ when it has the acetyl group.
Acetyl CoA
Which activated carrier molecule has a central role in metabolism and can be used to add two carbons in each successive cycle of fatty acid synthesis?
Acetyl CoA
What is the name of the high energy bonds in Acetyl CoA?
thioester bonds
What happens when the thioester bonds breaks?
It releases high energy
In animals, the breakdown of food molecules occurs in __ stages.
3
What is the first stage of the breakdown of food molecules in animals?
Break down of large food molecules in the mouth and the gut - occurs outside cells.
Where does glycolysis take place?
cytosol
Where does the conversion of pyruvate to acetyl groups on acetyl CoA take place?
mitochondrial matrix
What is stage 2 of the breakdown of food molecules in animals?
Intracellularly with glycolysis and ends with the conversion of the pyruvate to acetyl groups on acetyl CoA
Several types of organic molecules are converted to Acetyl CoA in the ____.
mitochondrial matrix
Where does the citric acid cycle take place?
Mitochondrial matrix
Where does oxidative phosphorylation take place?
Inner membrane
What is stage 3 of the breakdown of food molecules in animals?
Begins with the citric cycle and concludes with the phosphorylation.
What is the net result of the breakdown of food molecules in animals?
You CAN finish this! Hurray!
Food + O2 —> CO2 + ATP + NADH + H20
What are the inputs (reactants) for the breaking down of food molecules?
Food + O2
What are the products (outputs) for the breaking down of food molecules?
You go to the CAN and flush with water.
CO2 + ATP + NADH + H20