Bio100

Weak Bonds in Water

• Constantly formed and broken between two liquid water molecules.

• Options:

  • 1. Ionic Bond

  • 2. Hydrogen Bond

  • 3. Covalent Bond

Properties of Water

• Weak bonds between water molecules form because water is:

  • 1. A Liquid

  • 2. Polar

  • 3. Non-Polar

• Representation of water charge:

  • O has a partial negative charge (-)

  • H has a partial positive charge (+)

Thus, it creates attractions between different water molecules.

Bonds Within a Water Molecule

• Bonds within the molecule of water (between Oxygen and Hydrogens) are:

  • 1. Hydrogen bonds

  • 2. Covalent bonds

  • 3. Ionic bonds

Carbon Chemistry

• Carbon (Organic) Chemistry

  • Has four electrons in outer shell (can hold eight) - OCTET RULE: “rule of 8”

  • Can share electrons to form up to four covalent bonds

Organic Compounds

• Simplest organic compounds:

  • Hydrocarbons (hydrogen + carbon)

  • Organic molecules containing only carbon and hydrogen atoms

  • Simplest hydrocarbon: Methane (CH₄)

  • Examples of structural models:

    • Structural formula

    • Ball-and-stick model

    • Space-filling model

Hydrocarbons in Fuel

• Larger hydrocarbons: Main molecules in gasoline

• Key Point: Bond between C and H is a HIGH ENERGY BOND

  • Releases a lot of energy when broken

  • Example: Octane (C₈H₁₈) contains a lot of stored energy

Energy Content of Hydrocarbons

• Larger hydrocarbons are found in foods that provide most energy (calories per gram); these are:

  • Fats/Lipids

  • Foods high in calories are called “calorically dense”

Types of Biomolecules

• Four main types of biomolecules:

  • Nucleic Acids (DNA and RNA - very short term energy storage)

  • Proteins (structure and enzymes)

  • Lipids (fats - energy storage/protection)

  • Carbohydrates (energy and short-term storage)

Caloric Density of Biomolecules

• Which biomolecule has the most calories per gram?

  • 1. Fats/Lipids (most calorically dense)

  • 2. Carbohydrates

  • 3. Nucleic Acids

  • 4. Proteins

Biomolecular Structure

• Large biomolecules are formed through:

  • Dehydration reactions (monomers | polymers; water is released)

  • Hydrolysis reactions (break down polymers into monomers; requires water)

Nucleic Acids

• Types of nucleic acids include:

  • DNA

  • RNA

  • ATP (Adenosine Tri-Phosphate)

• Structure includes:

  • Nitrogen base

  • Phosphate group

  • Sugar

Functions of Nucleic Acids

• Temporary storage of chemical energy in ATP

• Encode information for entire organism as DNA

DNA and RNA Functionality

• DNA: Information storage (double-stranded)

• RNA: Information transfer and protein building (single-stranded)

• ATP: Short-term energy storage (single nucleotide with extra phosphates)

DNA Structure

• Nucleic acid building blocks linked into long chains called DNA strands.

• Sugar-phosphate backbone joins nucleotides with covalent bonds (strong).

• DNA forms a double helix: Two strands twisted together held by weak hydrogen bonds.

The Flow of Genetic Information

• Genetic information flows from DNA to RNA to protein:

  • Gene -> DNA -> RNA -> Amino acid sequence

Translation of RNA into Protein

• Examples of amino acid sequences translated from RNA codons

• Amino acid dictionary based on mRNA (mRNA-to-amino acid mapping charts)

Importance of DNA Mutations

• DNA mutations may occur from various exposures (radiation, viruses, etc.)

• Can result in changes in RNA, affecting protein synthesis.

• Example: Sickle Cell Anemia as a result of single DNA base mutation.

Glycogen and Blood Sugar Regulation

• glycogen: energy storage made from glucose links

• Insulin is released to convert glucose to glycogen when blood sugar rises; glucagon works in opposite.

• Glycemic Index: Foods categorized based on their effects on blood sugar levels.

Metabolism

• Metabolism: Essential chemical reactions converting organic molecules into energy forms.

• Energy released by breaking down C-H bonds.

• Types of energy: kinetic (movement) and potential (stored energy).

Enzymes and Catalysts

• Enzymes act as biological catalysts, speeding up reaction rates without being consumed in the process.

• Sensitive to environment (temperature, pH) affecting their functionality.

Nutritional Needs

• A balanced diet must provide energy, building materials, and other nutrients (vitamins and minerals) for overall health and proper function.

Healthy Diet Recommendations

• Limit saturated/trans fats and added sugars; embrace diversity in fruits, vegetables; adequate protein sources; control portions.

Understanding Fats

• Types of fats include saturated, unsaturated, and trans fats, affecting health outcomes differently based on their structure.

• Cholesterol management by understanding HDL (good) and LDL (bad) levels is crucial for heart health.

Conclusion and Final Notes

• Review major concepts of biomolecules and their roles in metabolism, energy, and genetic information.

• Understand the implications of dietary choices on health and chronic disease prevention.