Photosynthesis, Cellular Respiration, and DNA Function

Photosynthesis

Process converting light energy into chemical energy.

Balanced equation for photosynthesis

6CO2 + 6H2O → C6H12O6 + 6O2.

Chlorophyll

Green pigment located in chloroplasts; absorbs light.

Light-dependent reactions

Convert light energy to chemical energy; occur in thylakoids.

Calvin cycle

Uses ATP and NADPH to synthesize glucose; occurs in stroma.

C4 plants

Minimize photorespiration by spatial separation of processes.

CAM plants

Minimize photorespiration by temporal separation of processes.

Chemiosmotic phosphorylation

ATP production via proton gradient across membranes.

Photorespiration

Process where oxygen competes with carbon dioxide in plants.

Autotroph

Organism producing its own food from inorganic substances.

Heterotroph

Organism obtaining food by consuming other organisms.

Photons

Particles of light energy; fundamental unit of light.

Wavelength

Distance between successive peaks of a wave.

Pigments

Substances that absorb light; crucial for photosynthesis.

Photosystem

Complex of proteins and pigments; essential for light reactions.

Chlorophyll a

Primary pigment in photosynthesis; absorbs blue and red light.

Accessory pigments

Additional pigments aiding in light absorption.

Thylakoid

Membrane-bound compartment in chloroplasts; site of light reactions.

Stroma

Fluid-filled space in chloroplasts; site of Calvin cycle.

Mesophyll

Leaf tissue where photosynthesis primarily occurs.

Stomata

Pores on leaf surface; regulate gas exchange.

Bundle sheath cells

Cells surrounding vascular tissue; involved in C4 photosynthesis.

Types of respiration

Aerobic, anaerobic, and fermentation processes.

Stages of aerobic respiration

Glycolysis, Krebs cycle, electron transport chain.

Balanced equation for aerobic respiration

C6H12O6 + 6O2 → 6CO2 + 6H2O + ATP.

Glycolysis

Occurs in cytoplasm; produces pyruvate and ATP.

ATP production

Via substrate-level phosphorylation and oxidative phosphorylation.

Krebs cycle

Produces NADH, FADH2, ATP, and CO2.

ATP yield

Typically 36-38 ATP; varies due to efficiency.

Oxygen's role

Final electron acceptor in electron transport chain.

Types of fermentation

Lactic acid and alcoholic fermentation; produces 2 ATP.

DNA's components

Nucleotides: sugar, phosphate, and nitrogenous base.

Chargaff's rule

A=T and C=G in DNA composition.

Watson & Crick

Discovered double helix structure of DNA.

Central dogma

DNA → RNA → Protein; flow of genetic information.

RNA vs. DNA

RNA is single-stranded; DNA is double-stranded.

Types of RNA

mRNA, tRNA, rRNA; each has distinct roles.

Transcription location

Occurs in nucleus; RNA polymerase synthesizes RNA.

Promoter sequence

Region where RNA polymerase binds to initiate transcription.

Terminator sequence

Signals the end of transcription.

Translation location

Occurs in cytoplasm; synthesizes proteins from mRNA.

Stages of translation

Initiation, elongation, termination.

Genetic code

Set of rules translating mRNA into amino acids.

Transcribe and translate

AGGCATACCTGAGTC → Met-His-Leu-Arg.

Operons

Regulatory units controlling gene expression in bacteria.

Types of mutations

Point, insertion, deletion; alter genetic sequence.