Cellular Respiration
State the main stages of cellular respiration in order.
Glycolysis → Krebs Cycle → Electron Transport Chain
What two things do plants need from their environment to make glucose?
Carbon dioxide (CO₂) from the air and water (H₂O) from the soil, plus sunlight as the energy source.
Name the two fundamental properties of genetics that describe how traits are passed on and how organisms differ.
Inheritance and variation
What is DNA replication?
The process by which a cell makes an exact copy of its DNA
Which enzyme unwinds the DNA double helix?
Helicase
State where each stage of cellular respiration occurs in the cell.
Glycolysis → cytoplasm; Krebs cycle & ETC → mitochondria
In which organelle does photosynthesis occur?
Chloroplast
Why do living organisms need to change over time?
To adapt to their environment and increase survival
What are the three possible methods of DNA replication?
Conservative, semi-conservative, and dispersive
Which enzyme lays down RNA primers to start replication?
Primase
State the number of ATP molecules produced by each stage and the total yield. (Explain it, no direct answers)
Glycolysis = 2 ATP (net), Krebs = 2 ATP, ETC = about 32 ATP → total ≈ 36 ATP per glucose
Name the primary pigment involved in photosynthesis and explain why leaves appear green.
Chlorophyll; it absorbs most colors but reflects green and yellow light, which is why we see green leaves
What are the two main types of genetics studied?
Molecular genetics and Mendelian genetics
Which experiment proved that DNA replication is semi-conservative?
Meselson and Stahl experiment
Which enzyme joins Okazaki fragments on the lagging strand?
Ligase
State the main inputs and outputs of each stage of cellular respiration. (inputs and products)
Glycolysis: glucose → pyruvate + ATP + NADH;
Krebs: pyruvate → CO₂ + NADH + FADH₂ + ATP;
ETC: NADH/FADH₂ + O₂ → ATP + H₂O
What are the main reactants and products of photosynthesis?
Reactants: CO₂, H₂O, sunlight; Products: glucose (C₆H₁₂O₆) and O₂
What is genetic information, and what molecule stores it?
DNA; it stores the instructions for traits and cellular functions
List the main enzymes involved in DNA replication.
Helicase, DNA polymerase, ligase, primase, topoisomerase
Which enzyme adds new nucleotides to synthesize the new DNA strand?
DNA polymerase I & III
Explain step by step how energy from glucose ends up as ATP, including the role of NADH, FADH₂, and the proton gradient in the electron transport chain.
Glucose is broken into 2 pyruvate molecules in glycolysis, producing 2 ATP and 2 NADH.
Pyruvate is converted to Acetyl-CoA, producing NADH.
Acetyl-CoA enters the Krebs cycle, generating NADH, FADH₂, ATP, and CO₂.
NADH and FADH₂ donate electrons to the electron transport chain in the inner mitochondrial membrane.
Electron flow pumps H⁺ ions into the intermembrane space, creating a proton gradient.
H⁺ ions flow back through ATP synthase, driving the conversion of ADP → ATP.
Oxygen acts as the final electron acceptor, forming water.
Total ATP yield: ~36 ATP per glucose.
Explain step by step how sunlight energy is transformed into chemical energy in glucose, including the roles of chlorophyll, thylakoids, and the stroma.
1. Sunlight hits chlorophyll in the thylakoid membranes.
2. Light energy excites electrons, which travel through the electron transport chain in the thylakoid.
3. Water is split, producing O₂ and H⁺ ions.
4. Energy from the electrons and H⁺ gradient is used to convert ADP → ATP and NADP⁺ → NADPH.
5. ATP and NADPH provide energy and electrons for the Calvin cycle in the stroma, converting CO₂ into glucose.
DNA combines with ______ to make a _______, which is located in the cell ______
histones, chromosomes, nucleus
(take the experiment that we covered during the lesson as an example for this task) If a DNA molecule undergoes 5 rounds of semi-conservative replication, how many DNA strands will exist? How many hybrid molecules and how many light molecules?
After 5 generations, 2⁵ = 32 DNA molecules (strands paired into double helices)
2 hybrid molecules
254 light molecules
What are nucleases and what is their role in DNA replication?
Enzymes that cut DNA; they remove damaged or unnecessary DNA during replication and repair