Biology 41 Chapters 6/7 Flashcards

Cell Respiration vs. Photosynthesis

• Both processes utilize water, carbon dioxide, glucose, and oxygen, producing energy in different forms.
• Cellular respiration breaks down glucose with oxygen, producing ATP, carbon dioxide, and water.
• Photosynthesis combines carbon dioxide and water using solar energy to form glucose, releasing oxygen as a byproduct.
• Cellular respiration inputs: glucose and oxygen; Photosynthesis inputs: carbon dioxide and water.
• Autotrophs create organic matter independently, while heterotrophs must consume organic material for nutrients.

Importance of ATP in Cells

• ATP is the main energy currency for all living organisms, crucial for energy transformations.
• Cellular respiration, an aerobic process, converts food's chemical energy into ATP.
• Oxygen inhaled supports cellular respiration; carbon dioxide is expelled as a waste product.

Redox Reactions

• Redox stands for oxidation-reduction, involving electron transfer between species.
• Reduction refers to gaining electrons, while oxidation denotes losing electrons.
• Oxidation states reflect electron transfer occurring in chemical compounds.

Glycolysis

• "Splitting of sugars" to create two three-carbon molecules called pyruvates.
• NADH, an electron carrier, is produced via high-energy electrons from pyruvates.

Krebs Cycle

• Also known as citric acid cycle, it further processes products from glycolysis.
• Breaks down pyruvic acid to carbon dioxide, extracting energy.
• Converts pyruvate to Acetyl-CoA, enabling further ATP production.

Electron Transport Chain (ETC)

• Transports electrons, producing ATP by pumping hydrogen ions across mitochondrial membranes.
• The concentration gradient created stores potential energy, similar to a dam.

Role of NADH

• Functions as an electron shuttle, transporting electrons to necessary locations for energy production.

Carbon Content

• Glucose contains 6 carbons, pyruvic acid has 3 carbons, and Acetyl-CoA contains 2 carbons.

Role of Electrons and Hydrogen Ions in ETC

• Hydrogen ions (protons) create a concentration gradient; their flow back through the membrane releases energy.

Function of ATP Synthase

• Structures resembling turbines in mitochondria produce ATP using energy from electron transfers.

ATP Production Summary

• Glycolysis produces 2 ATP, Krebs cycle generates 2 ATP, and electron transport yields approximately 34 ATP, totaling 38.

Role of Oxygen in Cellular Respiration

• Oxygen acts as a terminal electron acceptor; its absence halts electron movement in the ETC and cellular respiration.

Chloroplasts and Photosynthesis

• Chloroplasts are located in leaf mesophyll cells; thylakoids increase surface area for photosynthetic reactions.
• Photosystems consist of pigments that absorb light energy, crucial for the photosynthetic process.

Energy Conversion in Photosynthesis

• Photosynthesis has two stages: light reactions convert solar to chemical energy, while dark reactions synthesize sugars.
• Sunlight is a form of electromagnetic energy necessary for the process.

Chlorophyll's Function

• Acts as a solar collector, absorbing light energy needed for photosynthesis.

Calvin Cycle

• Functions as a sugar factory within chloroplasts, using CO2, ATP, and NADPH to produce glyceraldehyde 3-phosphate (G3P).
• G3P is a precursor for glucose and other organic compounds.

Types of Plants Based on Carbon Fixation

• C3 plants directly absorb CO2 from air; prevalent and widely distributed.
• C4 plants, like cacti, adapt to conserve water by closing stomata yet perform photosynthesis efficiently.
• CAM plants open stomata at night for CO2 collection, thriving in arid climates.

Greenhouse Effect

• Caused by atmospheric CO2, the greenhouse effect warms the atmosphere.
• Associated with climate change, it is exacerbated by deforestation.