Atomic Structure and Cellular Organelles

Atomic Structure and Subatomic Particles

• Atoms are composed of subatomic particles: protons, neutrons, and electrons
• Protons and neutrons are located in the nucleus
• Electrons orbit the nucleus
• Protons have a positive charge, electrons have a negative charge, and neutrons are neutral
• Electrons play a role in chemical reactions by transferring or sharing electrons

Valence Electrons

• Valence electrons are electrons in the outermost shell of an atom
• They are important as they determine the chemical properties of an atom, including how it will bond with other atoms

Water

• Water is a polar molecule due to the unequal sharing of electrons between oxygen and hydrogen atoms

Functional Unit of Life

• The functional unit of life is the cell

Cell Compartments

• Cells have compartments called organelles
• Major compartments in cells are the cytoplasm and nucleus (not mentioned, but inferred)

Cellular Organelles: Ribosomes, Golgi Apparatus, Mitochondria

• Ribosomes are responsible for protein synthesis
• Golgi apparatus modifies, sorts, and packages proteins
• Mitochondria are involved in cellular respiration and energy production

Cellular Respiration

• Cellular respiration is the process by which cells break down glucose to produce ATP (energy)
• The equation for cellular respiration is a key concept and should be understood: C6H12O6 + 6O2 → 6CO2 + 6H2O + ATP

Glycolysis

• Glycolysis is the first step in cellular respiration
• It takes place in the cytoplasm
• Glycolysis does not require oxygen
• Glucose is converted to a 3-carbon molecule (pyruvate)

Citric Acid Cycle

• The citric acid cycle occurs in the mitochondria
• Pyruvate is not fed directly into the citric acid cycle; it is first converted to AcetylCoA

Electron Transport Chain

• Electron transport chain is a series of proteins located in the mitochondria
• It is crucial for ATP production during cellular respiration

ATP Production

• Most ATP is produced in the mitochondria via cellular respiration.

DNA and Genes

• DNA is a double-stranded molecule
• The structure of DNA includes base pairing (adenine with thymine, guanine with cytosine)
• Genes are segments of DNA that contain the instructions for building proteins
• A chromosome is packaged DNA

DNA Replication, Transcription, Translation

• DNA replication creates a copy of a DNA molecule
• Transcription is the process where DNA is converted to RNA
• Translation is where RNA directs the synthesis of proteins.
• Protein synthesis takes place on the ribosomes.

Mitosis and Meiosis

• Mitosis is cell division for growth and repair, resulting in two identical cells
• Meiosis is cell division for sexual reproduction, resulting in four non-identical cells; each with half the number of chromosomes (haploid)
• Mitosis happens to body cells, and meiosis takes place in reproductive cells
• Cells are called diploid when they have a full set of chromosomes
• RNA is not found in the middle of the DNA double helix

Chromosomes

• DNA is wrapped around proteins called histones