ap bio notes

Water's Role in Life

Water is involved in chemical reactions that maintain homeostasis and allows for the transport of materials (e.g., blood in animals and sap in plants).

Polarity of Water

Water is a polar molecule with partial charges at its poles, allowing it to form hydrogen bonds with other polar or charged molecules.

Cohesion

Water molecules attract each other, creating surface tension.

Adhesion

Water molecules attract and bond with other polar or charged molecules.

High Specific Heat

Water has high specific heat capacity due to hydrogen bonding, which allows organisms to maintain a stable internal temperature.

Capillary Action

Capillary action occurs when water adheres to tube surfaces in plant vascular tissue and moves upward due to cohesion and adhesion.

Main Elements of Life

Carbon, Hydrogen, Oxygen, Nitrogen (CHON) are the main elements, with trace elements critical for maintaining homeostasis.

Function of Carbon

Carbon is used to produce every biomolecule (carbohydrates, proteins, nucleic acids, lipids) and is recycled back into the environment by decomposers.

Role of Nitrogen

Nitrogen is essential for making proteins and nucleic acids. It is fixed from the atmosphere by bacteria and recycled by decomposers.

Significance of Phosphorus

Phosphorus is necessary for building nucleic acids and phospholipids, which are essential for cell membranes.

Functions of Carbohydrates

Carbohydrates serve as a short-term energy source, provide structural support (e.g., cellulose in plants), and are involved in energy storage.

Electronegativity in Biology

Electronegativity measures how strongly atoms attract bonding electrons, impacting molecular structure and behavior.

Effects of Polarity

Polarity results in molecules having partial positive and negative poles due to unequal sharing of electrons, crucial for interactions in biological systems.

Hydrogen Bonds

Hydrogen bonds are weak attractions between hydrogen atoms bonded to O, N, or F and another electronegative atom, playing a key role in molecular structure.

Covalent vs

Covalent bonds involve sharing of electrons, while ionic bonds result from the transfer of electrons, leading to charged ions.

Dehydration Synthesis

Dehydration synthesis is an anabolic process where water is removed to form a bond between monomers, creating polymers.

Hydrolysis

Hydrolysis is a catabolic process that uses water to break down polymers into monomers, releasing energy.

Types of Biomolecules

Carbohydrates, lipids, proteins, and nucleic acids are the four main types of biomolecules essential for life.

Carbon's Role in Life

Carbon has four valence electrons allowing it to form diverse structures with four covalent bonds, enabling the complexity needed for life.

Monomers, Dimers, and Polymers

Monomer:Basic building block; Dimer:Two monomers bonded; Polymer:Multiple monomers bonded together.

Anabolism

Anabolism is the process of building monomers into polymers, requiring energy (endergonic).

Catabolism

Catabolism is the process of breaking down polymers into monomers to generate ATP, releasing energy (exergonic).

Components of Nucleotides

A nucleotide consists of a sugar, a phosphate group, and a nitrogenous base.

Differences Between DNA and RNA

DNA is double-stranded and stable; RNA is single-stranded and less stable.

Primary Structure of Proteins

The primary structure is the sequence of amino acids linked by peptide bonds, determining the protein’s folding and function.

Secondary Protein Structures

Secondary structures form when hydrogen bonds create alpha helices and beta pleated sheets.

Tertiary Protein Structure

Tertiary structure is the final 3D folding of a protein, driven by R group interactions.

Quaternary Protein Structure

Quaternary structure occurs when multiple tertiary proteins join to form a larger complex.

Disulfide Bridges

Disulfide bridges are strong covalent bonds between sulfur atoms in cysteine amino acids, stabilizing protein structure.

Enzyme Function

Enzymes are specialized proteins that catalyze reactions by lowering activation energy.

Functions of Lipids

Lipids provide long-term energy storage, insulation, and make up cell membranes.

Saturated vs

Saturated fats are solid at room temperature; unsaturated fats are liquid and have double bonds.

Structural vs

Structural carbohydrates provide stability (e.g., cellulose); energy-storing carbohydrates allow rapid energy release.

Role of Phospholipids

Phospholipids form the main structure of cell membranes, creating a bilayer.

Specific Heat Capacity of Water

Water