A mole of light is called an Einstein, right? That is a mole of photons. And the characteristic absorbance in the 400 nanometer range displayed by molecules like cytochromes and photopigments is called the Soret band. The absorbance spectrum is the spectrum of light that a molecule, or rather could be a whole organism, will absorb. The action spectrum is the photosynthetic activity plotted over wavelength. And blue light is a type of light; it's not an absorbance. However, it is in this range, kind of a tricky answer choice there. And the alpha band, that is similar to the band, right? It was talked about at the same time, but the alpha band is a separate thing from the Soret band. The alpha band is the sort of characteristic absorbance. So the Soret band is shared by many molecules, but the alpha band is sort of what is the, like fingerprint for certain molecules if you will. It's unique to them. All right. That's all I have for this exam review. Good luck studying for your 6th exam and good luck studying for your final. I hope you guys do really well.
- 1. Introduction to Biochemistry4h 34m
- What is Biochemistry?5m
- Characteristics of Life12m
- Abiogenesis13m
- Nucleic Acids16m
- Proteins12m
- Carbohydrates8m
- Lipids10m
- Taxonomy10m
- Cell Organelles12m
- Endosymbiotic Theory11m
- Central Dogma22m
- Functional Groups15m
- Chemical Bonds13m
- Organic Chemistry31m
- Entropy17m
- Second Law of Thermodynamics11m
- Equilibrium Constant10m
- Gibbs Free Energy37m
- 2. Water3h 23m
- 3. Amino Acids8h 10m
- Amino Acid Groups8m
- Amino Acid Three Letter Code13m
- Amino Acid One Letter Code37m
- Amino Acid Configuration20m
- Essential Amino Acids14m
- Nonpolar Amino Acids21m
- Aromatic Amino Acids14m
- Polar Amino Acids16m
- Charged Amino Acids40m
- How to Memorize Amino Acids1h 7m
- Zwitterion33m
- Non-Ionizable Vs. Ionizable R-Groups11m
- Isoelectric Point10m
- Isoelectric Point of Amino Acids with Ionizable R-Groups51m
- Titrations of Amino Acids with Non-Ionizable R-Groups44m
- Titrations of Amino Acids with Ionizable R-Groups38m
- Amino Acids and Henderson-Hasselbalch44m
- 4. Protein Structure10h 4m
- Peptide Bond18m
- Primary Structure of Protein31m
- Altering Primary Protein Structure15m
- Drawing a Peptide44m
- Determining Net Charge of a Peptide42m
- Isoelectric Point of a Peptide37m
- Approximating Protein Mass7m
- Peptide Group22m
- Ramachandran Plot26m
- Atypical Ramachandran Plots12m
- Alpha Helix15m
- Alpha Helix Pitch and Rise20m
- Alpha Helix Hydrogen Bonding24m
- Alpha Helix Disruption23m
- Beta Strand12m
- Beta Sheet12m
- Antiparallel and Parallel Beta Sheets39m
- Beta Turns26m
- Tertiary Structure of Protein16m
- Protein Motifs and Domains23m
- Denaturation14m
- Anfinsen Experiment20m
- Protein Folding34m
- Chaperone Proteins19m
- Prions4m
- Quaternary Structure15m
- Simple Vs. Conjugated Proteins10m
- Fibrous and Globular Proteins11m
- 5. Protein Techniques14h 5m
- Protein Purification7m
- Protein Extraction5m
- Differential Centrifugation15m
- Salting Out18m
- Dialysis9m
- Column Chromatography11m
- Ion-Exchange Chromatography35m
- Anion-Exchange Chromatography38m
- Size Exclusion Chromatography28m
- Affinity Chromatography16m
- Specific Activity16m
- HPLC29m
- Spectrophotometry51m
- Native Gel Electrophoresis23m
- SDS-PAGE34m
- SDS-PAGE Strategies16m
- Isoelectric Focusing17m
- 2D-Electrophoresis23m
- Diagonal Electrophoresis29m
- Mass Spectrometry12m
- Mass Spectrum47m
- Tandem Mass Spectrometry16m
- Peptide Mass Fingerprinting16m
- Overview of Direct Protein Sequencing30m
- Amino Acid Hydrolysis10m
- FDNB26m
- Chemical Cleavage of Bonds29m
- Peptidases1h 6m
- Edman Degradation30m
- Edman Degradation Sequenator and Sequencing Data Analysis4m
- Edman Degradation Reaction Efficiency20m
- Ordering Cleaved Fragments21m
- Strategy for Ordering Cleaved Fragments58m
- Indirect Protein Sequencing Via Geneomic Analyses24m
- 6. Enzymes and Enzyme Kinetics13h 38m
- Enzymes24m
- Enzyme-Substrate Complex17m
- Lock and Key Vs. Induced Fit Models23m
- Optimal Enzyme Conditions9m
- Activation Energy24m
- Types of Enzymes41m
- Cofactor15m
- Catalysis19m
- Electrostatic and Metal Ion Catalysis11m
- Covalent Catalysis18m
- Reaction Rate10m
- Enzyme Kinetics24m
- Rate Constants and Rate Law35m
- Reaction Orders52m
- Rate Constant Units11m
- Initial Velocity31m
- Vmax Enzyme27m
- Km Enzyme42m
- Steady-State Conditions25m
- Michaelis-Menten Assumptions18m
- Michaelis-Menten Equation52m
- Lineweaver-Burk Plot43m
- Michaelis-Menten vs. Lineweaver-Burk Plots20m
- Shifting Lineweaver-Burk Plots37m
- Calculating Vmax40m
- Calculating Km31m
- Kcat46m
- Specificity Constant1h 1m
- 7. Enzyme Inhibition and Regulation 8h 42m
- Enzyme Inhibition13m
- Irreversible Inhibition12m
- Reversible Inhibition9m
- Inhibition Constant26m
- Degree of Inhibition15m
- Apparent Km and Vmax29m
- Inhibition Effects on Reaction Rate10m
- Competitive Inhibition52m
- Uncompetitive Inhibition33m
- Mixed Inhibition40m
- Noncompetitive Inhibition26m
- Recap of Reversible Inhibition37m
- Allosteric Regulation7m
- Allosteric Kinetics17m
- Allosteric Enzyme Conformations33m
- Allosteric Effectors18m
- Concerted (MWC) Model25m
- Sequential (KNF) Model20m
- Negative Feedback13m
- Positive Feedback15m
- Post Translational Modification14m
- Ubiquitination19m
- Phosphorylation16m
- Zymogens13m
- 8. Protein Function 9h 41m
- Introduction to Protein-Ligand Interactions15m
- Protein-Ligand Equilibrium Constants22m
- Protein-Ligand Fractional Saturation32m
- Myoglobin vs. Hemoglobin27m
- Heme Prosthetic Group31m
- Hemoglobin Cooperativity23m
- Hill Equation21m
- Hill Plot42m
- Hemoglobin Binding in Tissues & Lungs31m
- Hemoglobin Carbonation & Protonation19m
- Bohr Effect23m
- BPG Regulation of Hemoglobin24m
- Fetal Hemoglobin6m
- Sickle Cell Anemia24m
- Chymotrypsin18m
- Chymotrypsin's Catalytic Mechanism38m
- Glycogen Phosphorylase21m
- Liver vs Muscle Glycogen Phosphorylase21m
- Antibody35m
- ELISA15m
- Motor Proteins14m
- Skeletal Muscle Anatomy22m
- Skeletal Muscle Contraction45m
- 9. Carbohydrates7h 49m
- Carbohydrates19m
- Monosaccharides15m
- Stereochemistry of Monosaccharides33m
- Monosaccharide Configurations32m
- Cyclic Monosaccharides20m
- Hemiacetal vs. Hemiketal19m
- Anomer14m
- Mutarotation13m
- Pyranose Conformations23m
- Common Monosaccharides33m
- Derivatives of Monosaccharides21m
- Reducing Sugars21m
- Reducing Sugars Tests19m
- Glycosidic Bond48m
- Disaccharides40m
- Glycoconjugates12m
- Polysaccharide7m
- Cellulose7m
- Chitin8m
- Peptidoglycan12m
- Starch13m
- Glycogen14m
- Lectins16m
- 10. Lipids5h 49m
- Lipids15m
- Fatty Acids30m
- Fatty Acid Nomenclature11m
- Omega-3 Fatty Acids12m
- Triacylglycerols11m
- Glycerophospholipids24m
- Sphingolipids13m
- Sphingophospholipids8m
- Sphingoglycolipids12m
- Sphingolipid Recap22m
- Waxes5m
- Eicosanoids19m
- Isoprenoids9m
- Steroids14m
- Steroid Hormones11m
- Lipid Vitamins19m
- Comprehensive Final Lipid Map13m
- Biological Membranes16m
- Physical Properties of Biological Membranes18m
- Types of Membrane Proteins8m
- Integral Membrane Proteins16m
- Peripheral Membrane Proteins12m
- Lipid-Linked Membrane Proteins21m
- 11. Biological Membranes and Transport 6h 37m
- Biological Membrane Transport21m
- Passive vs. Active Transport18m
- Passive Membrane Transport21m
- Facilitated Diffusion8m
- Erythrocyte Facilitated Transporter Models30m
- Membrane Transport of Ions29m
- Primary Active Membrane Transport15m
- Sodium-Potassium Ion Pump20m
- SERCA: Calcium Ion Pump10m
- ABC Transporters12m
- Secondary Active Membrane Transport12m
- Glucose Active Symporter Model19m
- Endocytosis & Exocytosis18m
- Neurotransmitter Release23m
- Summary of Membrane Transport21m
- Thermodynamics of Membrane Diffusion: Uncharged Molecule51m
- Thermodynamics of Membrane Diffusion: Charged Ion1h 1m
- 12. Biosignaling9h 45m
- Introduction to Biosignaling44m
- G protein-Coupled Receptors32m
- Stimulatory Adenylate Cyclase GPCR Signaling42m
- cAMP & PKA28m
- Inhibitory Adenylate Cyclase GPCR Signaling29m
- Drugs & Toxins Affecting GPCR Signaling20m
- Recap of Adenylate Cyclase GPCR Signaling5m
- Phosphoinositide GPCR Signaling58m
- PSP Secondary Messengers & PKC27m
- Recap of Phosphoinositide Signaling7m
- Receptor Tyrosine Kinases26m
- Insulin28m
- Insulin Receptor23m
- Insulin Signaling on Glucose Metabolism57m
- Recap Of Insulin Signaling in Glucose Metabolism6m
- Insulin Signaling as a Growth Factor1h 1m
- Recap of Insulin Signaling As A Growth Factor9m
- Recap of Insulin Signaling1m
- Jak-Stat Signaling25m
- Lipid Hormone Signaling15m
- Summary of Biosignaling13m
- Signaling Defects & Cancer20m
- Review 1: Nucleic Acids, Lipids, & Membranes2h 47m
- Nucleic Acids 19m
- Nucleic Acids 211m
- Nucleic Acids 34m
- Nucleic Acids 44m
- DNA Sequencing 19m
- DNA Sequencing 211m
- Lipids 111m
- Lipids 24m
- Membrane Structure 110m
- Membrane Structure 29m
- Membrane Transport 18m
- Membrane Transport 24m
- Membrane Transport 36m
- Practice - Nucleic Acids 111m
- Practice - Nucleic Acids 23m
- Practice - Nucleic Acids 39m
- Lipids11m
- Practice - Membrane Structure 17m
- Practice - Membrane Structure 25m
- Practice - Membrane Transport 16m
- Practice - Membrane Transport 26m
- Review 2: Biosignaling, Glycolysis, Gluconeogenesis, & PP-Pathway3h 12m
- Biosignaling 19m
- Biosignaling 219m
- Biosignaling 311m
- Biosignaling 49m
- Glycolysis 17m
- Glycolysis 27m
- Glycolysis 38m
- Glycolysis 410m
- Fermentation6m
- Gluconeogenesis 18m
- Gluconeogenesis 27m
- Pentose Phosphate Pathway15m
- Practice - Biosignaling13m
- Practice - Bioenergetics 110m
- Practice - Bioenergetics 216m
- Practice - Glycolysis 111m
- Practice - Glycolysis 27m
- Practice - Gluconeogenesis5m
- Practice - Pentose Phosphate Path6m
- Review 3: Pyruvate & Fatty Acid Oxidation, Citric Acid Cycle, & Glycogen Metabolism2h 26m
- Pyruvate Oxidation9m
- Citric Acid Cycle 114m
- Citric Acid Cycle 27m
- Citric Acid Cycle 37m
- Citric Acid Cycle 411m
- Metabolic Regulation 18m
- Metabolic Regulation 213m
- Glycogen Metabolism 16m
- Glycogen Metabolism 28m
- Fatty Acid Oxidation 111m
- Fatty Acid Oxidation 28m
- Citric Acid Cycle Practice 17m
- Citric Acid Cycle Practice 26m
- Citric Acid Cycle Practice 32m
- Glucose and Glycogen Regulation Practice 14m
- Glucose and Glycogen Regulation Practice 26m
- Fatty Acid Oxidation Practice 14m
- Fatty Acid Oxidation Practice 27m
- Review 4: Amino Acid Oxidation, Oxidative Phosphorylation, & Photophosphorylation1h 48m
- Amino Acid Oxidation 15m
- Amino Acid Oxidation 211m
- Oxidative Phosphorylation 18m
- Oxidative Phosphorylation 210m
- Oxidative Phosphorylation 310m
- Oxidative Phosphorylation 47m
- Photophosphorylation 15m
- Photophosphorylation 29m
- Photophosphorylation 310m
- Practice: Amino Acid Oxidation 12m
- Practice: Amino Acid Oxidation 22m
- Practice: Oxidative Phosphorylation 15m
- Practice: Oxidative Phosphorylation 24m
- Practice: Oxidative Phosphorylation 35m
- Practice: Photophosphorylation 15m
- Practice: Photophosphorylation 21m
Practice: Photophosphorylation 2: Study with Video Lessons, Practice Problems & Examples
A mole of light, known as an Einstein, refers to a mole of photons. The characteristic absorbance in the 400 nanometer range, associated with molecules like cytochromes, is termed the Soray band. The absorbent spectrum indicates the light absorbed by a molecule, while the action spectrum reflects photosynthetic activity across wavelengths. The alpha band serves as a unique fingerprint for specific molecules, distinguishing them from the Soray band. Understanding these concepts is crucial for grasping the mechanisms of photosynthesis and light absorption in biological systems.
Practice
Video transcript
Here’s what students ask on this topic:
What is an Einstein in the context of photophosphorylation?
An Einstein in the context of photophosphorylation refers to a mole of photons. This term is used to quantify the amount of light energy involved in photosynthetic processes. One mole of photons, or one Einstein, contains Avogadro's number of photons (approximately 6.022 × 1023 photons). This concept is crucial for understanding the energy input required for photosynthesis, as the absorption of photons by photosynthetic pigments drives the conversion of light energy into chemical energy.
What is the Soray band and its significance in photosynthesis?
The Soray band is a characteristic absorbance in the 400 nanometer range, commonly associated with molecules like cytochromes and photopigments. This band is significant in photosynthesis because it represents the specific wavelengths of light that these molecules can absorb. The absorbed light energy is then used to drive the photosynthetic reactions, making the Soray band crucial for understanding how different pigments contribute to the overall efficiency of photosynthesis.
What is the difference between the absorbent spectrum and the action spectrum?
The absorbent spectrum is the range of wavelengths of light that a molecule or organism can absorb. It shows which wavelengths are absorbed and to what extent. In contrast, the action spectrum represents the photosynthetic activity plotted against different wavelengths of light. It indicates which wavelengths are most effective in driving photosynthesis. While the absorbent spectrum shows potential absorption, the action spectrum shows actual photosynthetic performance, highlighting the wavelengths that are most useful for the organism's energy conversion processes.
What is the alpha band and how does it differ from the Soray band?
The alpha band is a unique absorbance characteristic that serves as a fingerprint for specific molecules. Unlike the Soray band, which is shared by many molecules and is generally found in the 400 nanometer range, the alpha band is unique to individual molecules. This uniqueness allows scientists to identify and differentiate between various molecules based on their specific absorbance properties. Understanding the alpha band is important for studying the specific roles and functions of different molecules in biological systems.
Why is understanding the action spectrum important in the study of photosynthesis?
Understanding the action spectrum is important in the study of photosynthesis because it reveals which wavelengths of light are most effective in driving the photosynthetic process. By plotting photosynthetic activity against different wavelengths, researchers can identify the optimal light conditions for maximum photosynthetic efficiency. This knowledge is crucial for improving agricultural practices, optimizing growth conditions in controlled environments, and developing artificial photosynthetic systems. The action spectrum helps in understanding how different pigments contribute to the overall energy conversion process in photosynthesis.