Energy, Photosynthesis, and Cellular Respiration

Practice flashcards covering cellular energy, thermodynamics, enzymes, photosynthesis steps, and cellular respiration pathways.

What is the 1st Law of Thermodynamics state regarding energy?

Energy is neither created nor destroyed.

What is ATP, and what is its full chemical name?

ATP stands for Adenosine Triphosphate. It is a nucleotide that temporarily stores energy used by cells for cellular work.

How does the 2nd law of thermodynamics define entropy, and why is universe entropy increasing?

Entropy is a measure of disorder or randomness in our universe. Universe entropy is increasing because heat energy is constantly lost during energy transformations and heat energy is disordered.

What is the difference between oxidation and reduction in chemical reactions?

Oxidation is the loss of electrons from an atom or molecule which releases energy (becoming more positive), whereas reduction is the gain of electrons by an atom or molecule which requires energy (becoming more negative).

What mnemonic is presented to remember oxidation and reduction?

Leo the lion goes ger (Leo: lose electron oxidation; ger: gain electron reduction).

What is an electron transport chain?

A sequential series of membrane proteins participating in linked oxidation-reduction reactions.

How does ATP release stored potential energy for cellular work?

By removing the endmost phosphate group through hydrolysis.

What is an enzyme, and how does it function in biochemical reactions?

An enzyme is a protein that acts as a catalyst to speed up a chemical reaction without being consumed by lowering the activation energy.

What is a substrate and where does it bind on an enzyme?

A substrate is the molecule an enzyme acts on, and it binds to the enzyme's active site.

What is the chemical formula for glucose produced in photosynthesis?

$$C_6H_{12}O_6$$

What three inputs are required for photosynthesis to occur?

Sunlight, Carbon dioxide ($CO_2$), and Water ($H_2O$).

Where do the light reactions of photosynthesis take place, and what are their products?

Light reactions occur in the thylakoids of chloroplasts. They require water and light to produce ATP, NADPH, and oxygen gas as a byproduct.

Where do the carbon reactions of photosynthesis occur, and how do they build sugar?

Carbon reactions occur in the stroma of the chloroplast. RuBP, powered by ATP and NADPH produced during light reactions, removes carbon atoms from $CO_2$ to build sugar molecules.

What process occurs during Glycolysis in cellular respiration?

Glucose is split in half to form pyruvate, transferring some energy to electrons and using some to form ATP.

What process occurs during the Kerbs Cycle?

A derivative of pyruvate is oxidized, releasing $CO_2$ and transferring more energy to electrons.

What is the final electron acceptor in the Electron Transport Chain (ETC) during cellular respiration?

Oxygen is the final electron acceptor.

Where in the cell do Glycolysis, the Kerbs Cycle, and the Electron Transport Chain (ETC) take place?

Glycolysis takes place in the cytosol, while the Kerbs Cycle and Electron Transport Chain (ETC) take place in the mitochondria.

How can components of fats and amino acids be utilized in cellular respiration pathways?

Components of fats can be converted to pyruvate or acetyl CoA. Amino acids can be converted to pyruvate, acetyl CoA, or Kerbs cycle intermediates.