Photosynthesis, Cellular Respiration, and Protein Synthesis

Photosynthesis, Cellular Respiration, and Protein Synthesis

Photosynthesis

The Four Main Biomolecules used in photosynthesis

1. Lipids: provide insulation and produce long term energy

1. The monomer= glycerol and 3 fatty acids
2. The polymer= trygliceride

2. Nucleic Acids: code the genetic information of living things

1. The monomer= nucleotide
2. The polymer (three different types)

1. DNA
2. RNA
3. ATP

3. Carbohydrates: work as and provide a fast source of energy
4. Proteins: help with transport, provide storage, give energy, conduct gene expression, and enzymes

Carbohydrates

• The monomer= monosaccharide 
• The polymer= disaccharides or polysaccharide

• Then two monosaccharides combine, they lose a water molecule

Chloroplasts

• Photosynthesis takes place in the chloroplasts of plants
• These chloroplasts are in the leaves of plants
• There are 2 stages

• Light Independent Reactions
• Light Dependent Reactions

Light Dependent Reactions

• They take place in the thylakoid membrane 
• Light dependent reactions require constant light energy
• The chloroplasts absorb this light energy and use it to produce 2 compounds:

• ATP (cellular energy)
• NADPH (electron carrier)

• Light splits H2O into O2 and the H+ attaches to NADP+ to make NADPH
• Photosystems are large complexes of protein and pigment that collect light 
• Electrons are passed through water and end up in NADPH 

Light Independent Reactions

• Takes place in stoma/stomata and doesn’t require light in any way
• Uses ATP and NADPH to make three carbon sugar molecules called glycerol triphosphate

Cellular Respiration

Mitocondria

• Cellular respiration occurs in the mitochondria to make ATP
• ATP is what created cellular energy
• There are two forms of respiration

• Areobic respiration

• Requires O2
• 36 ATP are needed

• Anaerobic respiration

• No O2 required

• Alchoholic Fermentation
• Lactic Acid Fermentation

• 2 ATP required

Glycosis

1. Takes place in the cytoplasm
2. Glucose molecules are split into two using two ATP molecules
3. Creates four ATP molecules
4. Net two ATP molecules and two pyruvate acid molecules
5. Net two NADH+H+
6. If there is oxygen present then it is automatically aerobic respiration, 

oxygen present = aerobic

Citric acid/Krebs cycle- aerobic respiration

• The matrix of mitochondria 
• One pyruvic acid molecule goes through at a time
• Net production

• 8 NADPH
• 2 FADH2
• 2 ATP
• 6 CO2 

Electron Transport Chain

• Electrons come from NADH and FADH2
• H+ cannot move throught the membrane, so protein channels move up
• H+ concentration builds up, moves back through the protein called ATP synthase creating ATP
• Yeilds 30 to 32 ATP
• Yeilds 6 H2O

Types of Anareobic Respiration

• Alchoholic Fermantation

• Bread rises (yeast)

• Lactic Acid

• Builds up in muscles
• Helps make yogurt and cheese

Protein Synthesis

Ribosomes

• Not an organelle, has no membrane
• Found in all cells
• Free floating in cytoplasm or attached to rough endoplasmic reticulum
• Site of protein synthesis
• Ribosomes in rough ER:

• Make proteins specifically to be used by cell membrane or to be exported to other parts of the body

• Golgi- packages and sorts proteins and lipids
• Lysosome- breaks down cells and cell structures 
• Make proteins specifically designed to be used within the cell

RNA

• One nucleotide chain
• Contains nitrogen base uracil (U) instead of thymine (T)
• Contains sugar ribose
• The three types of RNA

• Messenger RNA (mRNA)
• Ribosomal RNA (rRNA)
• Transfer RNA (tRNA)

Protein synthesis steps

Important: everything is read in 3’s

Transcription

• Occours in nucleus
• Transfer of genetic information in DNA to mRNA
• Step 1: Initiation

• RNA polymerase binds to DNA signaling it to unwind

• Step 2: Elongation

• Addition of nucleotides to the mRNA strand

• Step 3: Termination

• Ending of transcription, mRNA is complete, dtaches from DNA

Translation

• mRNA made in the nucleus from DNA
• Codons match antocodons
• Amino acids “pop off” tRNA and attach to eachother though peptide bond

Gene Mutations

Substitution/ Point Mutation

• When a nucleotide is coded improperly and substituted 

Insertion

• When and extra nucleotide is inserted, causing a frameshift

Deletion

• When one of the nucleotides gets deleted, causing a frameshift 

Inversion

• When a sequence of nucleotides gets invented