Water (H2O)

Honelako gehiago

RAMAS DE LA QUIMICA

by FRANKLKIN MURILO THERAN

chemical reaction

by Kanyanat wawsawad

The characteristics of living things

by Lady Moreno

Year 8

by peter hill

Water (H2O)

Water in Chemical Reactions

Dehydration Synthesis Water is removed to join two molecules together. Ex. Glucose + Glucose → Maltose + H₂O

Carboydrates

- Primary Energy Source - Energy Storage - Structural Support

Polysaccharides (Complex Carbohydrates)

Structural Polysaccharides

- Cellulose (plant cell walls, indigestible to humans) - Chitin (fungal cell walls, exoskeletons)

Storage Polysaccharides

- Starch (plants) → Stores glucose for energy - Glycogen (animals) → Stored in liver & muscles

Disaccharides (Two Monosaccharides Linked)

- Ex. Sucrose, Lactose, Maltose - Formed by dehydration synthesis - Broken down by hydrolysis

Monosaccharides (Simple Sugars)

- Ex. Glucose, Fructose, Galactose - Function: Quick energy source

Hydrolysis Water used to split large molecules into smaller ones. Ex. Sucrose + H₂O → Glucose + Fructose

Nucleic Acids

Function

ATP: Provides energy for cellular activities

RNA: Helps build proteins

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Nucleotides

- Sugar (Deoxyribose in DNA, Ribose in RNA) - Phosphate group - Nitrogenous base (A, T/U, G, C)

ATP (Adenosine Triphosphate)

- Energy carrier in cells - High-energy phosphate bonds

RNA (Ribonucleic Acid)

- Helps in protein synthesis - Single-stranded - Bases: A-U, G-C

Types:

tRNA → Brings amino acids to ribosomes

rRNA → Forms part of ribosomes

mRNA→ Carries genetic code from DNA to ribosomes

DNA (Deoxyribonucleic Acid)

- Stores genetic information - Double-stranded (double helix) - Bases: A-T, G-C

pH & Water (Acids, Bases, and Neutrality)

pH Scale (0-14)

Acids (pH < 7): High concentration of H⁺ ions

Bases (pH > 7): High concentration of OH⁻ ions

Neutral (pH = 7): Pure water has equal amounts of H⁺ and OH⁻ ions.

Properties of Water

Hydrophobicity - Non-polar and repel water - Hydrophobic molecules form separate layers rather than dissolving

Lipids

- Energy storage - Cell membrane structure - Insulation & Protection - Hormone production - Waterproofing

Types

Waxes

- Waterproofing

Steroids

- Four fused carbon rings - Hormone signaling, cell membrane stability

Phospholipids

- 1 glycerol + 2 fatty acids + phosphate group - Form cell membranes (phospholipid bilayer) - Hydrophilic head & Hydrophobic tail → Forms selective barrier

Triglycerides (Fats & Oils)

- 1 glycerol + 3 fatty acids - Long-term energy storage, insulation, protection

Unsaturated fats

One or more double bonds (liquid at room temp

Saturated fats

No double bonds (solid at room temp)

Universal Solvent -Water dissolves polar and ionic compounds -Important for transporting nutrients and chemical reactions in cells.

Proteins

Structure

Levels of Protein Structure

Secondary Structure

Alpha helices or beta sheets formed by hydrogen bonding

Tertiary Structure

3D folding due to interactions between R groups

Quaternary

Multiple polypeptide chains interacting

Primary Structure

Sequence of amino acids (polypeptide chain)

Amino Acids (Building Blocks)

Peptide Bond

20 types of amino acids

R group (side chain, varies for each amino acid)

Carboxyl group (COOH)

Amino group (NH₂)

Functions

Immune Defense

Antibodies are proteins that help protect against pathogens

Signaling

Hormones like insulin act as chemical messengers

Transport

Hemoglobin carries oxygen in red blood cells

Structural Support

Proteins like collagen and keratin provide strength and structure

Enzymatic Activity

- Proteins act as enzymes to speed up chemical reactions. - Ex. Amylase breaks down starch into sugars.

High Heat of Vaporization -Takes lots of energy to convert water from liquid to gas. -Sweating and transpiration help organisms cool down as water evaporates.

Adhesion -Water molecules stick to other polar or charged surfaces. -Leads to capillary action, which helps water move through plant roots and blood vessels.

Cohesion -Water molecules are attracted to each other due to hydrogen bonding. -Creating surface tension, allowing insects to walk on water.

Water's Molecular Structure

- 2 hydrogens 1 oxygen - Shared by covalent bonds - V shaped

- Oxygen atoms, slight negative charge, meaning they are greedy for electrons. - Hydrogen atoms,slight positive charge, meaning they want to give away their electrons.

Due to this polarity, all water molecules are attracted to one another and once they're all stuck together, those are called hydrogen bonds. The positive pole around one hydrogen atom will bond to the negative pole around the oxygen atoms of another water molecule.