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Chapter 4
Difference between potential energy and kinetic energy
Potential energy is stored energy, while kinetic energy is the energy of motion
First law of thermodynamics
Energy cannot be created or destroyed, only transferred or transformed
Role of ATP in cell biology
ATP is the primary energy currency of cells
ATP cycle consists of endergonic (energy-requiring) and exergonic (energy-releasing) reactions
Difference between endergonic vs exergonic reactions
Endergonic reactions require energy input, while exergonic reactions release energy
Function and characteristics of enzymes
Enzymes are biological catalysts that speed up chemical reactions
Enzymes are specific to certain substrates and have an active site where the substrate binds
Activation energy and active site
Activation energy is the energy required to start a chemical reaction
Active site is the region of the enzyme where the substrate binds
Regulation of enzymes by pH, salt concentration, and temperature
Enzymes have optimal pH, salt concentration, and temperature for activity
Changes in these factors can denature enzymes and affect their function
Difference between positive and negative feedback enzyme regulation
Positive feedback amplifies the initial stimulus, while negative feedback counteracts it
Terms to know: concentration gradient, diffusion, osmosis, hypertonic, hypotonic, isotonic
Concentration gradient is the difference in concentration between two areas
Diffusion is the movement of molecules from an area of high concentration to low concentration
Osmosis is the diffusion of water across a selectively permeable membrane
Hypertonic solution has a higher solute concentration than the cell
Hypotonic solution has a lower solute concentration than the cell
Isotonic solution has the same solute concentration as the cell
Effects of hypertonic, hypotonic, and isotonic solutions on cells
Hypertonic solution causes cells to shrink (crenation)
Hypotonic solution causes cells to swell and potentially burst (lysis)
Isotonic solution maintains cell shape and volume
Difference between active transport and facilitated diffusion
Active transport requires energy to move molecules against their concentration gradient
Facilitated diffusion uses transport proteins to move molecules down their concentration gradient
Passive transport and examples
Passive transport is the movement of molecules without the input of energy
Examples include diffusion and osmosis
Membrane transport requiring transport proteins
Active transport and facilitated diffusion require transport proteins to move substances across the membrane
Difference between endocytosis and exocytosis
Endocytosis is the process of bringing substances into the cell by engulfing them with the cell membrane
Exocytosis is the process of releasing substances from the cell by fusing vesicles with the cell membrane
Chapter 5
Basic details of photosynthesis and its overall net reaction
Photosynthesis is the process by which plants convert sunlight, carbon dioxide, and water into glucose and oxygen
Overall net reaction: 6 CO2 + 6 H2O + light energy → C6H12O6 + 6 O2
Terms to know: photon, chlorophyll, photosystem, rubisco
Photon is a particle of light
Chlorophyll is the pigment that captures light energy in plants
Photosystem is a complex of proteins and pigments that carries out the initial steps of photosynthesis
Rubisco is the enzyme responsible for carbon fixation in the Calvin cycle
Colors of light absorbed and reflected by plants
Plants absorb red and blue light for energy
Plants reflect green light, which is why they appear green in color
Role of accessory pigments in increasing absorbed light colors
Accessory pigments broaden the range of light colors that can be absorbed for energy
Needs and products of Light Dependent and Light Independent reactions
Light Dependent reactions require light energy and produce ATP and NADPH
Light Independent reactions (Calvin cycle) use ATP and NADPH to convert CO2 into glucose
Photosystem I and photosystem II products
Photosystem I produces NADPH
Photosystem II produces ATP
Chemiosmotic phosphorylation in light-dependent reactions
Chemiosmotic phosphorylation is the process of ATP synthesis using the energy from a proton gradient
It plays a role in the light-dependent reactions of photosynthesis
Chapter 6
Basic details of aerobic respiration and its overall net reaction
Aerobic respiration is the process by which cells convert glucose and oxygen into carbon dioxide, water, and ATP
Overall net reaction: C6H12O6 + 6 O2 → 6 CO2 + 6 H2O + ATP
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Stages of aerobic respiration: Glycolysis, Kreb's Cycle, and Electron Transport Chain
Glycolysis occurs in the cytoplasm, Kreb's Cycle in the mitochondria, and Electron Transport Chain in the inner mitochondrial membrane
Glycolysis requires glucose and produces pyruvate, ATP, and NADH
Kreb's Cycle requires pyruvate and produces ATP, NADH, FADH2, and CO2
Electron Transport Chain requires NADH and FADH2 and produces ATP and water
Stage of aerobic respiration producing the most ATP
Electron Transport Chain produces the most ATP
Final electron acceptor of the electron transport chain
Oxygen is the final electron acceptor
Substrate level phosphorylation and chemiosmotic phosphorylation in aerobic respiration
Glycolysis and Kreb's Cycle use substrate level phosphorylation
Electron Transport Chain uses chemiosmotic phosphorylation
Enzyme synthesizing ATP via chemiosmotic phosphorylation
ATP synthase synthesizes ATP via chemiosmotic phosphorylation
Net gain of ATP molecules from glucose breakdown via aerobic respiration
36-38 ATP molecules are produced from the breakdown of glucose via aerobic respiration
Energy harvest from proteins and fats in mitochondria
Mitochondria can also harvest energy from proteins and fats consumed
Products of the two types of fermentation
Alcoholic fermentation produces ethanol and carbon dioxide
Lactic acid fermentation produces lactic acid
Role of fermentation in restoring NAD+ supply
Fermentation serves to restore NAD+ supply when oxygen levels are low or absent
Stage of aerobic respiration synthesizing ATP when oxygen levels are low or absent
Glycolysis can synthesize ATP when oxygen levels are low or absent