Biology Chapter 2 Test Topics

Atoms

• Parts of an atom: protons, neutrons, and electrons protons and neutrons are on the inside electrons outside protons: positive neutrons: no charge electrons: negative atoms: Neutral charge
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• Pie de imagen: atoms neutral charge

chemical bonds: ionic vs convalent

• an ionic bond is formed when one or more electrons are transferred from one atom to another and a convalent bond is formed when electrons are shared between atoms
• charged atoms are produced when they either lose electrons (positive) or gains electrons (negative)

Examples of Convalent&Ionic Bonds

• Ionic: Sodium and chlorine in table salt; a sodium atom loses one valence electron and becomes a sodium ion and a chlorine atom gains an electron becoming a charged ion
• Convalent: In a water molecule, each hydrogen atom shares two electrons with the oxygen atom

water, acids, and bases

• structure of water: 2 hydrogen atoms 1 oxygen atom
• up to 60% of a human is water
• polarity is when the molecule has both a positively and negatively charged end and it's produced when the electrons are unequally shared
• the hydrogen end of the molecule is slightly positive and the oxygen is negative
• it's important for water to break down the things in our bodies and that's why it's a universal solvent

Hydrogen Bonds

• Hydrogen bonds are the bonds between two hydrogen atoms and an example is the attraction between the hydrogen atom on one water molecule and the oxygen atom on another water molecule
• Cohesion is an attraction between molecules of the same substances, and an adhesion is an attraction between molecules of different substances

Characteristics of acids, bases, buffers, and pH scale

• acids are any compounds that forms H+ ions in solution and acidic solutions contain higher concentrations of H+ ions than pure water and have pH values below 7
• bases are compounds that produce hydroxide ions in solution and basic solutions contain lower concentrations of H+ ions than pure water and have pH values above 7
• buffers are weak acids or bases that can react with strong acids or bases to prevent sharp, sudden changes in pH and it's dissolved compounds
• a pH scale is a measurement system used to indicate the concentration of H+ ions than OH- ions.

Macromolecules

• carbon can form millions of different large and complex structures and has 4 valence electrons and can bond with many elements
• Monomers are small units that can join together together with other small units to form polymers
• six elements that are found in macromolecules are carbon hydrogen oxygen nitrogen and phosphorus

Carbohydrates

• Monomer: Glucose and it's made of carbon, hydrogen, and oxygen atoms
• Example: pasta and bread
• Function: it gives strcutures to plants and is a main source of energy

Lipids

• Building Blocks: Glycerol and fatty acids and carbon and hydrogen atoms
• Example: insulation and fats, oils, and wzxes
• Function: to store energy

Proteins

• Building Blocks: amino acids and nitrogen, carbon, hydrogen, and oxygen atoms
• Example: fibrous
• Function: help to carry out chemical reactions, transport small molecules in and out of cells, and fight diseases

Nucleic Acids

• Building Blocks: nucleotides and CHONP ATOMS
• Example: DNA/RNA
• Function: nucleic acids store and transmit genetic information

Enzymes

• Enzymes belong to proteins and it speeds up chemical reactions that take place in cells
• Activation energy is the energy needed to get a reaction started and enzymes provide a site where reactants can be brought together to react, reducing the energy needed for a reaction
• Substrates are the reactants of enzyme-catalyzed reactions
• Induced fit is the substrate binding to a site on the enzyme called the active site a
• At the end of a reaction, the enzyme becomes free to start the process again because it's bound with a substrate at the beginning of the process
• Enzymes can be affected by anything that influences a chemical reaction