Cellular Respiration Processes

Glycolysis

• Location: Cytoplasm
• Products: 2 pyruvate, 2 ATP, and 2 NADH molecules
• Glucose is oxidized
• NAD+ is reduced to NADH

Krebs Cycle

• Location: Mitochondria
• Products per cycle: 2 CO2, 3 NADH, 1 FADH2, and 1 ATP, cycle happens twice for each glucose
• Pyruvate is oxidized
• NAD+ and FAD are reduced to NADH and FADH2

Electron Transport Chain (ETC)

• Location: Mitochondria
• Products: 34 ATP and water
• NADH and FADH2 are oxidized
• Oxygen is reduced and forms water

Anaerobic Pathways

• Function: Produce ATP in the absence of oxygen
• Lactic acid fermentation: Produces lactic acid in muscles during heavy exercise
• Alcohol fermentation: Produces alcohol and CO2 in yeast

Oxidation and Reduction

• Oxidation: Loss of electrons or hydrogen
• Reduction: Gain of electrons or hydrogen

Locations of Glycolysis, Krebs Cycle, and ETC

• Glycolysis: Cytoplasm
• Krebs Cycle: Mitochondria
• ETC: Inner membrane of the mitochondria

Blockers of ETC

• Cyanide: Stops the final step of the ETC, preventing ATP production
• DNP: Makes the ETC less efficient by causing proton leaks

Final Electron Acceptor in ETC

• Oxygen (O2) is the final electron acceptor
• Water (H2O) is formed when it combines with electrons and hydrogen

Light-Dependent Reactions

• Location: Chloroplasts
• Products: ATP, NADPH, and oxygen (O2)
• Water (H2O) is oxidized to release oxygen
• NADP+ is reduced to NADPH

Light-Independent Reactions (Calvin Cycle)

• Products: Glucose (C6H12O6)
• NADPH is oxidized
• Carbon dioxide (CO2) is reduced to glucose

Final Electron Acceptor in Photosynthesis (Light-Dependent Reactions)

• NADP+ is the final electron acceptor
• NADPH is formed after picking up electrons

Photosynthesis Reaction

• Overall reaction: 6CO2 + 6H2O + light → C6H12O6 + 6O2
• Oxygen comes from the splitting of water molecules
• Glucose is made from carbon dioxide, using energy from the sun

C3 Plants

• Use the Calvin cycle to make sugar
• In hot conditions, energy is wasted

C4 Plants

• Have an extra step to avoid wasting energy
• Suited for hot, dry climates

DNA

• Stores genetic information
• Double-stranded
• Made of deoxyribose sugar

RNA

• Helps with making proteins
• Single-stranded
• Made of ribose sugar
• Uses uracil (U) instead of thymine (T)

Transcription

• A cell makes a copy of a segment of DNA into RNA (mRNA)
• Location: Nucleus

Translation

• A cell reads mRNA and uses it to build a protein
• Location: Cytoplasm at the ribosome

History of DNA

• Griffith: Bacteria can change into different types
• Avery et al.: DNA carries genetic information
• Hershey and Chase: DNA carries genetic information, not protein
• Watson and Crick: Discovered the double-helix structure of DNA

DNA to RNA and Back

• DNA to RNA: Transcription turns DNA into mRNA
• DNA bases: A-T, G-C
• RNA bases: A-U, G-C, RNA uses U instead of T
• RNA to DNA: Reverse transcription makes DNA from RNA

tRNAs and Ribosome Sites

• tRNAs bring amino acids to the ribosome
• A site: Where the tRNA with the next amino acid enters
• P site: Where the growing protein chain is attached to the tRNA

Codons

• Codons are groups of 3 nucleotides in mRNA
• Codons tell the ribosome which amino acid to add
• There are 64 possible codons
• Only 20 amino acids are used in proteins

Reverse Transcriptase

• Enzyme that turns HIV's RNA into DNA
• Allows the virus to insert its genetic material into human cells

Plasmids, Restriction Enzymes, and Ligases

• Plasmids: Small pieces of DNA that bacteria can share and are used for genetic engineering
• Restriction Enzymes: Enzymes that cut DNA at specific places
• Ligases: Enzymes that join pieces of DNA together

Bacterial Expression of Proteins

• Bacteria can be modified to carry human genes
• Bacteria produce human or viral proteins using a plasmid
• Restriction enzymes cut and insert genes
• Ligase seals them

DNA Fingerprinting

• A method for identifying people based on DNA patterns
• Used in criminal investigations

Mutations

• Substitution: One base in DNA is swapped for another
• Deletion: A base is removed from the DNA sequence
• Addition: A base is added to the DNA sequence