photosynthesis + cellular respiration

Light dependent reactions

reactions of photosynthesis that use energy from light to produce ATP and NADPH

Light independent reactions

Use ATP + NADPH (high energy electrons), carbon dioxide gas --> organic molecules (glucose). Carbohydrates are made using CO2 from the atmosphere

Chlorophyll

molecules that absorb light and their electrons become excited, moving to a higher energy state. These high-energy electrons are used to do work (make ATP) and are then transferred to carrier molecules called NADPH

Mesophyll tissue

Most of the photosynthetic activity occurs in the…and is in the center of the leaf

Starting reactants of aerobic cellular respiration

Glucose + oxygen

Electron carrier molecules

NADH + FADH2

Glucose contains…

chemical energy + high-energy electrons recieved while being built during photosynthesis

What is the primary source of energy for almost all living cells?

The sun

What process do plants, algae, and some bacteria use to capture sunlight energy?

Photosynthesis

What structures in plant leaf cells are responsible for photosynthesis?

Chloroplasts

What are thylakoids?

Internal membranes within chloroplasts, stacked in columns called grana

What is the stroma?

A semi-liquid substance that surrounds the thylakoids in chloroplasts

What are the three main stages of photosynthesis?

1. Capturing energy from sunlight, 2. Producing ATP and NADPH, 3. Making carbohydrates from CO2

What are the two types of reactions in photosynthesis?

Light-dependent reactions and light-independent reactions (Calvin cycle)

What do light-dependent reactions produce?

ATP and NADPH

What is the Calvin cycle?

The light-independent reactions that produce organic molecules from CO2

What is the overall equation for photosynthesis?

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

What are photons?

Packets of energy that make up light

What is the electromagnetic spectrum?

The range of all types of light energy, including visible light

What is chlorophyll?

The primary pigment in plants that captures light energy

What are accessory pigments?

Pigments that absorb light wavelengths not captured by chlorophyll

What happens during the light-dependent reactions in photosystems?

Light energy is captured, electrons are excited and transferred, producing ATP and NADPH

What is chemiosmosis?

The process where protons flow through ATP synthase to produce ATP

What is the role of rubisco in the Calvin cycle?

It fixes carbon dioxide from the atmosphere

What is photorespiration?

A process where rubisco fixes oxygen instead of carbon, hindering photosynthesis

What adaptations do C4 plants have for photosynthesis in hot climates?

They use different cells and reactions to fix carbon, preventing CO2 depletion

What is crassulacean acid metabolism (CAM)?

A process where some plants perform photosynthesis at night using the C4 pathway

What are bundle-sheath cells?

Cells in C4 plants that trap CO2 for photosynthesis

How many times must the Calvin cycle turn to form one glucose molecule?

Six times

What is the significance of the Calvin cycle in relation to light-dependent reactions?

It recycles ADP and NADP+ for use in the light-dependent reactions

What is the process of obtaining energy by breaking down organic molecules called?

Cellular respiration

What are the two main stages of cellular respiration?

Glycolysis and Krebs cycle

Where does glycolysis occur?

In the cytoplasm

Does glycolysis require oxygen to generate ATP?

No, it does not require oxygen.

What is the main product of glycolysis?

Two three-carbon pyruvate molecules

What is the role of NAD+ in glycolysis?

It accepts electrons and hydrogen atoms to form NADH.

What is substrate-level phosphorylation?

The process of generating ATP by directly transferring a phosphate group to ADP.

What occurs during the Krebs cycle?

Energy-rich electrons are harvested through a series of oxidation reactions.

What is produced from the oxidation of pyruvate in the presence of oxygen?

Acetyl-CoA

What happens to one of the carbons from pyruvate during its oxidation?

It is cleaved off and released as CO2.

What is the significance of redox reactions in cellular respiration?

They involve the transfer of electrons, which retain potential energy.

What are oxidation and reduction in the context of cellular respiration?

Oxidation is the loss of electrons, while reduction is the gain of electrons.

What is the overall energy yield from glycolysis?

Only two ATP molecules are produced per glucose molecule.

What is the final compound formed from pyruvate after oxidation?

Acetyl-CoA

What is the role of coenzyme A (CoA) in cellular respiration?

It combines with the two-carbon fragment of pyruvate to form acetyl-CoA.

What is the function of NADH in cellular respiration?

It carries hydrogen atoms and energetic electrons.

What is the importance of glycolysis in organisms?

It allows organisms to derive energy from food in the absence of oxygen.

What is the relationship between glucose and ATP in glycolysis?

Glucose is phosphorylated and broken down to produce ATP.

What are redox reactions also known as?

Oxidation-reduction reactions.

What happens to the energy stored in organic molecules during cellular respiration?

It is released and used to produce ATP.

How many ATP molecules are generated for each pyruvate during glycolysis?

Two ATP molecules.

What is the first step of oxidative respiration?

The oxidation of pyruvate.

What is the significance of the electron transport chain in cellular respiration?

It powers the production of ATP using electrons from NADH and FADH2.

What is the primary product of glycolysis?

Two ATP molecules are produced for each molecule of glucose.

What is the role of pyruvate in cellular respiration?

Pyruvate is oxidized to form acetyl-CoA in the presence of oxygen.

What enzyme cleaves a carbon from pyruvate during its oxidation?

Pyruvate dehydrogenase cleaves one carbon from pyruvate.

What happens to the carbon that is cleaved from pyruvate?

It leaves as part of a CO2 molecule.

What is formed when pyruvate is oxidized?

Acetyl-CoA is formed from the oxidation of pyruvate.

What is the fate of acetyl-CoA when ATP levels are low?

Acetyl-CoA enters the Krebs cycle.

What occurs to acetyl-CoA when ATP levels are high?

Acetyl-CoA is diverted to fat synthesis for energy storage.

What are the three stages of the Krebs cycle?

1. Acetyl-CoA binds to a four-carbon molecule. 2. Two carbons are removed as CO2, producing NADH and ATP. 3. The four-carbon molecule is recycled, extracting more electrons to form NADH and FADH2.

How many turns of the Krebs cycle occur per glucose molecule?

Two turns of the Krebs cycle occur for each glucose molecule.

What is the role of NADH and FADH2 in cellular respiration?

They transfer electrons to the electron transport chain.

What is chemiosmosis?

Chemiosmosis is the process where protons diffuse back into the mitochondrial matrix, driving ATP synthesis.

What is the final electron acceptor in the electron transport chain?

Oxygen is the final electron acceptor, forming water.

What is fermentation?

Fermentation is the process that allows ATP production in the absence of oxygen by regenerating NAD+.

What are the two types of fermentation in eukaryotes?

Ethanol fermentation in yeasts and lactic acid fermentation in animals.

What happens to glucose during cellular respiration?

Glucose is entirely consumed, transforming its energy into ATP, NADH, and FADH2.

What is the starting material for the Krebs cycle?

The starting material is a four-carbon molecule, oxaloacetate.

What is produced alongside ATP in the Krebs cycle?

NADH and FADH2 are also produced during the Krebs cycle.

What is the significance of the electron transport chain?

It facilitates the transfer of electrons and the pumping of protons to generate ATP.

How do cells metabolize food other than glucose?

Cells digest complex molecules into simpler subunits that enter cellular respiration at different steps.

What are the main types of macromolecules that cells can metabolize?

Cells can metabolize nucleic acids, proteins, polysaccharides, and lipids.

What is the end product of lactic acid fermentation?

Lactate is produced during lactic acid fermentation.

What is the role of coenzyme A (CoA) in metabolism?

CoA is involved in the formation of acetyl-CoA from pyruvate.

What is the overall equation for cellular respiration?

Glucose + O2 → CO2 + H2O + ATP.

What is produced during the oxidative decarboxylation of pyruvate?

NADH and CO2 are produced during oxidative decarboxylation.

What is the importance of NAD+ in cellular respiration?

NAD+ acts as an electron carrier, accepting electrons to form NADH.