Units 4-7 Flashcards
What is kinetic energy?
Energy in motion, such as a moving car.
What is potential energy?
Stored energy, such as a stretched rubber band.
What is the First Law of Thermodynamics?
Energy cannot be created or destroyed, only transferred or transformed.
What is the Second Law of Thermodynamics?
Energy transfer increases entropy (disorder) in the universe.
What are endergonic reactions?
Reactions that absorb energy and have positive ΔG.
What are exergonic reactions?
Reactions that release energy and have negative ΔG.
What is catabolism?
The process that breaks down molecules to release energy.
What is anabolism?
The process that builds up molecules using energy.
What are enzymes?
Biological catalysts that lower the activation energy of a reaction.
What is oxidation?
Involves the loss of electrons.
What is reduction?
Involves the gain of electrons.
What are the reactants of photosynthesis?
Carbon dioxide (CO₂), water (H₂O), and sunlight.
What are light-dependent reactions?
The phase of photosynthesis that occurs in the thylakoid membranes.
What is the Calvin cycle?
The light-independent reactions of photosynthesis that occur in the stroma.
What is water’s role in photosynthesis?
Water is split in the light-dependent reactions, releasing oxygen (O₂) and providing electrons and protons needed for ATP and NADPH production.
What is chlorophyll a?
Absorbs light for photosynthesis.
What is chlorophyll b?
Assists in light absorption.
What are carotenoids?
Protect against excessive light.
What is rubisco?
The enzyme that fixes carbon dioxide in the Calvin cycle.
What are autotrophs?
Organisms that produce their own food (e.g., plants).
What are heterotrophs?
Organisms that obtain energy by consuming other organisms (e.g., animals).
What is the primary usable form of energy in a cell?
ATP (adenosine triphosphate).
What are the steps of aerobic cellular respiration?
1) Glycolysis (cytoplasm), 2) Pyruvate oxidation (mitochondrial matrix), 3) Krebs cycle (mitochondrial matrix), 4) Electron transport chain (inner mitochondrial membrane).
What is ATP synthase?
Synthesizes ATP by using the energy from proton movement across the mitochondrial membrane.
How much ATP is produced in aerobic respiration?
About 36-38 ATP per glucose molecule.
What is fermentation?
A process that does not use oxygen and produces less ATP.
What are the products of fermentation?
Lactic acid (in animals), ethanol and CO₂ (in yeast).
What happens to pyruvic acid in fermentation?
Converted into another product to regenerate NAD⁺ so glycolysis can continue.
What is the central dogma of biology?
DNA → RNA → Protein.
What are nucleotides?
Made of a phosphate group, a sugar (deoxyribose in DNA, ribose in RNA), and a nitrogenous base.
What are the nitrogenous bases in DNA?
A, T, C, G.
What are the nitrogenous bases in RNA?
A, U, C, G.
What are Chargaff’s Rules?
The amount of A equals T, and the amount of C equals G in a DNA molecule.
What is the double-helix structure of DNA?
DNA consists of two strands twisted around each other, with bases paired in the centre.
What does antiparallel mean in DNA?
DNA strands run in opposite directions.
What does semi-conservative mean in DNA replication?
Each new DNA molecule has one old and one new strand.
What are Okazaki fragments?
Short DNA segments on the lagging strand during replication.
What are the functions of helicase?
Unwinds DNA.
What are the functions of polymerase?
Adds new nucleotides.
What are the functions of ligase?
Joins Okazaki fragments.
What are telomeres?
Protective end caps of chromosomes.
What is telomerase?
Extends telomeres to prevent loss of genetic information.
What is PCR?
Used for amplifying DNA sequences for analysis.
