Metabolism
What is the first law of thermodynamics?
energy cannot be created or destroyed; it can only be converted from one form to another
Which substances are reduced in cellular respiration? Which are oxidized?
Oxidized: glucose reduced to CO2
What is the formula for photosynthesis?
light + 6CO2 + 6H2O → C6H12O6 + 6O2 + ATP
What are the components of a nucleotide?
phosphate group
sugar (ribose=RNA, deoxyribose=DNA)
nitrogenous base (C, T, A, G, U)
What is the central dogma?
a theory stating that genetic information flows only in one direction, from DNA, to RNA, to protein, or RNA directly to protein.
What is second law of thermodynamics?
any spontaneously occurring process will always lead to an escalation in the entropy (S) of the universe
Which steps of cellular respiration are oxidative phosphorylation versus substrate-level phosphorylation?
Glycolysis: substrate-level
Pyruvate Oxidation: n/a
Citric Acid Cycle: substrate-level
Electron Transport Chain: oxidative
Where does photosynthesis take place?
chloroplasts/thylakoids
How is the sugar backbone of DNA built (outside of ladder)? How are the bases held together (ring of ladder)?
Sugar backbone built through dehydration reaction
Bases held together by hydrogen bonds
What are the differences between DNA and RNA?
DNA: stores genetic information for the cell, double stranded, deoxyribose, ATGC, formed in replication, found in nucleus
RNA: codes for amino acids and acts as a messenger between DNA molecules and the ribosomes, single stranded, ribose, AUGC, formed in transcription, found all over cell
What is entropy?
measure of the molecular disorder, or randomness, of a system
What is the difference between fermentation and aerobic respiration?
Fermentation: no O2 present, yields 2 ATP
Aerobic Respiration: O2 present, yields 26-28 ATP
Is photosynthesis endergonic or exergonic?
both
What is Replication? Transcription? Translation?
Replication: DNA replicates
Transcription: DNA to RNA
Translation: RNA to proteins
What is the difference between regulatory DNA and coding DNA?
Regulatory: they control when, where, and how much genes are expressed
Coding: sequence of DNA that codes for protein
Distinguish between exergonic and endergonic reactions in terms of free energy change
Exergonic reactions release energy which leads to a loss (negative) of free energy.
Endergonic reactions consume energy which leads to a gain (positive) of free energy.
What are the net inputs and outputs of each stage of cellular respiration?
Glycolysis: Inputs- glucose, Outputs- 2 NADH, 2 ATP, 2 pyruvate
Pyruvate Oxidation: Inputs- pyruvate, Outputs- acetyl coA, 2 NADH, 2 CO2
Citric Acid Cycle: Inputs- acetyl coA, Outputs- 2 FADH2, 2 ATP, 2 NADH
Electron Transport Chain: Inputs- 10 NADH, 2 FADH2, Outputs- 26-28 ATP, H2O
What are the inputs and outputs of light reactions of photosynthesis?
Inputs: light, water, ADP/P, NADP+
Outputs: oxygen, NADPH, ATP
Identify the leading and lagging strand in DNA replication.
Leading strand: strand that runs 3' to 5' towards replication fork
Lagging strand: strand that runs 5' to 3' towards replication fork
Describe process of transcription
1) Initiation: binding of RNA polymerase to the promoter in DNA
2) Elongation: One strand of DNA serves as the template for RNA synthesis
3) Termination: lease of the newly synthesized mRNA from the elongation complex, poly(A) tail is added to the new 3' end of the messenger RNA strand
Describe the structure and function of ATP including how it is used to transfer energy from an exergonic
reaction to an endergonic reaction and how it is used to do work in the cell.
Hydrolysis of ATP to ADP and P is exergonic (energy goes to do work in cell)
Synthesis of ATP from ADP and P is endergonic
Summarize the steps of oxidative phosphorylation.
1) Electrons captured in NADH and FADH2
2) NADH and FADH2 donate electrons to electron transport chain (H+ pumped against concentration gradient into intermembrane space of mitochondria)
3) Potential energy of H+ gradient is used to power ATP synthesis by ATP synthase (H+ pumped back into mitochondrial matrix, potential energy turns ATP synthase to make ATP)
What are the inputs and outputs of dark reactions of photosynthesis?
Inputs: CO2, ATP, NADPH
Outputs: sugar (G3P), NADP+, ATP/P
Identify the proteins involved in replication and identify their role
DNA polymerase: enzyme that sticks new bases onto DNA strands
Helicase: untwists DNA
DNA ligase: puts in final piece to connect fragments together
Single-stranded binding protein: bind to and stabilize single-strand DNA
Topoisomers: relieves strain caused by tight twisting ahead of replication fork by breaking and rejoining DNA strands
Primase: starts replication by adding nucleotides
Telomeres: special nucleotide sequences at end of DNA strands (prevents shortening of DNA)
Describe process of translation
1) Initiation: small subunit of the ribosome binds with the messenger RNA (mRNA) sequence
2) Elongation: a number of amino acids are added to the chain and linked together by peptide bonds to form polypeptide bonds
3) Termination: the ribosome reaches a stop codon (UAG, UAA, or UGA), a release factor will bind to the stop codon and cause the amino acid chain to be released and the ribosome subunits to separate.