Respiration

Cellular respiration: the process by which cells break down food to produce energy

Redox reaction: a reaction that involves the transfer of electrons between chemical species

Oxidation: a chemical reaction where a molecule loses electrons, often by transferring them to oxygen, resulting in the release of energy that cells can utilize for various biological processes

Reduction: one molecule gives up electrons to another molecule. The molecule that loses electrons is oxidized, and the molecule that gains electrons is reduced.

How are photosynthesis and cellular respiration coupled?: the products of photosynthesis (glucose and oxygen) are the reactants for cellular respiration, while the products of cellular respiration (carbon dioxide and water) are the reactants for photosynthesis

photosynthesis: Convert light energy into chemical energy in the form of sugars, using water and carbon dioxide, and releasing oxygen as a byproduct

What is the role of NAD+?: acts as a key coenzyme in cellular metabolism, primarily functioning as an electron carrier in redox reactions, transferring electrons during energy production processes like glycolysis and the citric acid cycle, ultimately contributing to the synthesis of ATP (cellular energy)
How do electron transport chains generate energy?:

What is the starting reactant for glycolysis?: 1 glucose (6 carbon)

How many ATP and NADH are formed in glycolysis?: 4 ATP, 2 NADH

Where does glycolysis take place?: Outside the mitochondria in the cytoplasm

What is the end product of glycolysis?: 2 ATP, 2 NADH, 2 Pyruvates

When does fermentation take place?: in the muscles of animals when they need energy faster than the blood can supply oxygen

Explain the role of NAD+ and NADH in fermentation.: oxidation of NADH to form NAD⁺

What is the difference between lactic acid fermentation and alcohol fermentation?: Lactic acid fermentation produces lactic acid, while alcoholic fermentation produces ethanol and carbon dioxide

What is the starting reactant for the preparatory step (also called transition or transport step)?: 2 Pyruvates

How many NADHs are formed in this step?: 2 acetyl-CoAs, 2 molecules of CO2, and 2 NADHs.

What does pyruvate become by the end of the transportation step?: Acetyl-CoAs

Where does the transition step take place?: Starts in the cytoplasm, ends in the mitochondria

What is the starting reactant for krebs?: 2 Acetyl-CoA

How many ATP and NADH and FADH are formed in krebs?: 2 ATP, 6 NADH, 2 FADH

Where does krebs take place?: Inside the mitochondria

What is the end product of krebs?: 2 ATP, 6 NADH2, 2 FADH2, 4 CO2

Explain how ATP is made by the electron transport chain?: The kinetic energy from the electron falling

Section 7.5

In class we will say each glucose molecule can produce 38 ATPs, what are some reasons the yield is usually not this high.: the cost of moving pyruvate (from glycolysis), phosphate, and ADP (substrates for ATP synthesis) into the mitochondria

Explain how other molecules (not just glucose) are used for energy.: Fats, proteins, and other carbohydrates are modified into intermediate products of glycolysis and the citric acid cycle

Photosynthesis: convert light energy into chemical energy in the form of sugars, using carbon dioxide and water, and releasing oxygen as a byproduct

Stomata: a pore found in the epidermis of leaves, stems, and other organs, that controls the rate of gas exchange between the internal air spaces of the leaf and the atmosphere.

Stroma: provide volume around the different structures inside the chloroplast for protection

Thylakoids: pouch-like sacs that are bound to a membrane in the chloroplasts of a plant cell. They contain a pigment, called chlorophyll, that absorbs light

Redox: refers to chemical reactions involving the transfer of electrons

Oxidation: The loss of electrons

Reduction: The gain of electrons

Light reaction: capture energy from sunlight, which they change to chemical energy that is stored in molecules of NADPH and ATP

Calvin cycle: Carbon dioxide is glued together using the energy (ATP) and electrons (NADPH) form the light reactions, sugar is formed)

What is the difference between the two inner membranes of chloroplasts and mitochondria?: The inner membrane in mitochondria is folded into cristae. The inner membrane in the chloroplast forms flattened sacs called thylakoids

What is being reduced in photosynthesis and what is being oxidized?: carbon dioxide is reduced (gains electrons) to form sugars, while water is oxidized (gains electrons) to release oxygen

Section 6.2
Chlorophyll: the name of the green pigment that plants use to make food during a process called photosynthesis

NADP+ and NADPH: a redox pair, with NADP+ being the oxidized form and NADPH the reduced form

What is the role of pigments?: absorb specific wavelengths of light and reflect others, giving objects their color

Why is it that most leaves are green?: Because green light is not absorbed/it is reflected.

Explain how ATP and NADH are made in Photosystem II and I.: Water is split producing an electron and oxygen, Sunlight excites electrons, Electron goes through ETC (either cyclic or noncyclic),

Explain the relationship between a photosystem and an electron.: capture light energy and use it to excite electrons

How does an electron transport chain generate ATP?: The kinetic energy of the electron falling down the electron transport chain

Section 6.3
Where does the energy to fix carbon in the Calvin cycle come from?: produced during the light-dependent reactions of photosynthesis

How are ATP and NADPH used to make a sugar (G3P) in the Calvin cycle?”: use their stored energy to convert the three-carbon compound, 3-PGA, into another three-carbon compound called G3P. This type of reaction is called a reduction reaction, because it involves the gain of electrons.

What do plants do with all the sugar they make during the day?: Photosynthesis, or save for cellular respiration at night

How many carbons glucose, pyruvate, and acetyl have.: What are 6, 3, 2?

The phases where CO2 is released: What are transition and Krebs

How many NADHs are produced in the Krebs cycle?: 6 NADH are produced

Stage that takes place in the cytoplasm: What is glycolysis?

Where does electron transport take place?: The inner membrane of the mitochondria

The amount of FADH generated from one acetyl in the Krebs cycle: 1 FADH

The energy from this is used to pump hydrogen ions (protons) into the outer compartment of the mitochondria: What is the kinetic energy of electrons?

This is the element that initially grabs the electron at the end of electron transport: Oxygen

What becomes alcohol/lactate?: pyruvates

The amount of NADH formed in glycolysis from one glucose: 2 NADH

The amount of ATP formed in electron transport from one molecule of glucose: 34 ATP

Where do light independent reactions take place: Thylakoid membrane

The electron used in photosystem 1 and 2 came from where?: Water

The falling electron in photosystem II is directly used to do this: What is pump hydrogen ions (protons) into the thylakoid space?

In noncyclic flow the electrons end up in this: NADPH

The color that is usually not absorbed very well by pigments in plants: Green

What 3 things needed for sugar: CO2, NADPH, ATP

Where light independent reactions take place: Stroma

The process the chloroplast goes through if it needs more ATP than NADPH: Cyclic electron flow

What do plants do with a glucose at night: Aerobic respiration

The protons flow by facilitative diffusion through ATP synthase from this area to this area: Thylakoid space and stroma

Where does fermentation take place in the cell?: Cytoplasm

How many ATP you gain from one molecule of glucose during fermentation: 2 ATP

The role that pyruvate plays in fermentation: Accepts electron from NADH

The reason beer has both alcohol and CO2: End products of fermentation by yeast

What is Lactate or lactic acid: This is what pyruvate become in human skeletal muscles when we undergo fermentation

• 1. Electron Transfer by NADH and FADH2:

  • NADH and FADH2, produced during glycolysis and the citric acid cycle, donate their electrons to the ETC.

  • NADH transfers its electrons to Complex I, while FADH2 transfers its electrons to Complex II.

• 2. Establishment of an Electrochemical Gradient:

  • As electrons move through the ETC, protons (H+) are pumped from the mitochondrial matrix into the intermembrane space, creating a proton gradient.

  • This gradient stores potential energy, which is then used to drive ATP synthesis.

• 3. Splitting of Oxygen to form Water:

  • At the end of the ETC, electrons are passed to molecular oxygen (O2), which combines with protons (H+) to form water (H2O).

• 4. Generation of ATP by ATP Synthase:

  • The proton gradient generated by the ETC drives ATP synthase, an enzyme that uses the energy of the gradient to synthesize ATP from ADP and inorganic phosphate.