Biology Chapter: Sugars and Proteins

Simple Sugars and Polymers

• Monosaccharides: Simple sugars, like glucose.
• Disaccharides: Sugars formed from two monosaccharides.
• Polysaccharides: Long chains of monosaccharides (e.g., starch, glycogen).
• Glycogen: Animal energy storage.
• Starch: Plant energy storage.
• Cellulose: Plant cell wall component, strong carbohydrate.
• Monomer: A small molecule that joins to form a larger molecule (polymer).
• Polymer: A large molecule formed from many repeating smaller units (monomers).
• Glycosidic linkage: Bond connecting sugar molecules.

Protein Structure and Function

• Amino acids: The building blocks of proteins, with 20 different types.
• Polypeptide: A chain of amino acids.
• Primary structure: The sequence of amino acids.
• Secondary structure: Folding patterns (alpha helix or beta sheet) due to hydrogen bonds.
• Tertiary structure: The overall 3D shape of the protein, formed by interactions between R groups.
• Quaternary structure: Multiple polypeptide chains interacting.
• Hydrophobic: Water-repelling.
• Hydrophilic: Water-attracting.
• Denature: When a protein loses its shape and function due to environmental factors (heat, pH, chemicals).
• R group: determines how the protein folds and interacts, influencing properties.

Lipids

• Lipid: Fats and certain oils that do not mix with water.
• Fatty acid: A long carbon chain component of lipids.
• Fat: A type of lipid used for energy storage.
• Phospholipid: A lipid that forms cell membranes.
• Steroid: Lipids with a ring structure, (example, hormones).

Nucleic Acids (DNA and RNA)

• DNA: Molecule that stores genetic information.
• RNA: Molecule that helps make proteins.
• Nucleotide: Building block of DNA and RNA; composed of sugar, phosphate, and nitrogenous base.
• Nucleoside: nucleotide without the phosphate group.
• Antiparallel: DNA strands that run in opposite directions (5' to 3' on one, and 3' to 5' on the other strand)
• Nitrogenous bases:
• Purines (Adenine, Guanine)
• Pyrimidines (Cytosine, Thymine, Uracil)

Cell Structures and Organelles

• Prokaryotic cell: Simple cell without a nucleus or membrane-bound organelles (e.g., bacteria).
• Eukaryotic cell: Complex cell with a nucleus and membrane-bound organelles (e.g., plants, animals).
• Ribosomes: Organelles that build proteins.
• Rough endoplasmic reticulum (ER): ER with ribosomes, involved in protein synthesis and modification.
• Smooth ER: ER without ribosomes, involved in lipid synthesis.
• Golgi apparatus: Organelle that modifies, sorts, and packages proteins.
• Lysosomes: Organelles that contain digestive enzymes.
• Centrioles: Organelles involved in cell division.
• Chloroplasts: Organelles for photosynthesis.
• Central vacuole: Large fluid-filled sac within plant cells, maintaining turgor pressure.
• Cell wall: Rigid outer layer of plant cells.

Cell Transport

• Passive transport: Movement of molecules from high to low concentration without energy.
• Active transport: Movement of molecules from low to high concentration requiring energy (ATP).
• Facilitated diffusion: Passive transport assisted by transport proteins.
• Channel proteins: Transport proteins that form channels.
• Carrier proteins: Transport proteins that change shape to move molecules.
• Osmosis: The diffusion of water across a membrane.

Osmosis and Tonicity

• Hypertonic: Solution has a higher solute concentration than the cell, water exits the cell. (Cell shrinks)
• Isotonic: Solution has an equal solute concentration to the cell, no net water movement. (Cell stays the same)
• Hypotonic: Solution has a lower solute concentration than the cell, water enters the cell. (Animal cells burst, plant cells become turgid)