The Building Blocks of Molecules and Macromolecules

Life is made up of matter.

Mater is made of elements, which is ___.

• ex.

Matter is made up of elements, which is substances that can not be broken down into other substances.

• ex. gold, carbon, etc.

• Atom – ___

  • Protons are ____

  • Neutrons are ____

  • Electrons are ____

  • The + (protons) and – (electrons) charges ___ 

• Atom – smallest unit of an element

  • Protons are positively charged atomic particles with a mass of 1 and +1 charge (located in nucleus).

  • Neutrons are atomic particles with no charge and a mass of 1 (located in nucleus).

  • Electrons are negatively charged atomic particles with negligible mass and -1 charge (located around the nucleus).

  • The + (protons) and – (electrons) charges balance each other in a neutral atom (0 charge). 

Periodic Table of Elements

• Atomic number:

  • Changing this number would change the identity of the element.

• Atomic mass =

  • Number of neutrons =

• Atomic number: identifies the element and represents the number of protons. 

  • Changing this number would change the identity of the element.

• Atomic mass = # of protons (atomic number) + # of neutrons

  • Number of neutrons = Atomic mass – Atomic number 

Isotopes are ____

• Some isotopes, like ____, can be used to date fossils.

Ions result when ___

• gaining electron(s) results in ___

• losing electron(s) results in ___

Isotopes are different forms of the same element that have the same number of protons, but different numbers of neutrons.

• Some isotopes, like those of carbon and potassium, can be used to date fossils.

Ions result when the number of electrons varies.

• Gaining electron(s) results in a negative charge.

• Losing electron(s) results in a positive charge.

Chemical Bond Types

Chemical bonds hold atoms together to form molecules.

• Covalent bonds are the ____.

  • They form when two atoms ___.

    • Nonpolar covalent bonds –

    • Polar covalent bonds –

      • ex.

  • Do covalent bonds dissociate (come apart) in water?

• Covalent bonds form when two atoms share an electron

  • They the strongest bond.

    • Nonpolar covalent bonds – the electrons are shared equally.

    • Polar covalent bonds – the electrons are shared unequally (the electron spends more time closer to one atom than the other)

      • Ex. a water molecule is held together by polar covalent bonds

    • They don’t come apart in water.

Chemical Bond Types

Chemical bonds hold atoms together to form molecules.

• Ionic bonds – ____

  • Ionic bonds are ____

  • Do they dissociate in water?

  • Ex.

• Ionic bonds – form when an electron is transferred from one atom to another → Form ions of opposite charges → These opposite charges attract each other, which holds the ions together. 

  • Fairly strong bond.

  • They do dissociate in water. 

  • Ex. Table Salt: Na donates an electron to Cl → forming ions (Na⁺/Cl^-) → ionic bond will hold them together to form NaCl (table salt). 

Chemical Bond Types

Chemical bonds hold atoms together to form molecules.

• Hydrogen bonds –

  • Is the ___ bond of them all.

  • Ex.

• Hydrogen bonds – form between the slightly-positive hydrogen atoms from a polar molecule and the slightly-negative atoms from another polar molecule. 

  • Weakest bond of them all.

  • Ex. Water molecules are held together with hydrogen bonds. 

What are other words for “water loving” and “water fearing”?

What type of molecules are each?

• Polar molecules are hydrophilic – “water loving”

• Nonpolar molecules are hydrophobic – “water fearing”

• Cohesion – the force that causes__

  • Surface tension is the capacity of a substance to __

• Adhesion – the force that causes __

  • ex.

Cohesive and adhesive forces allow a plant to draw water in through its roots.

• Cohesion – the force that causes similar molecules (ex. water molecules) to stick together due to hydrogen bonding

  • Surface tension is the capacity of a substance to hold together when under stress. 

• Adhesion – the force that causes molecules of different substances to stick together

  • ex. Water molecules will also “stick” to other polar molecules by forming hydrogen bonds. 

Cohesive and adhesive forces allow a plant to draw water in through its roots.

• Carbohydrates ___

  • Monosaccharides –

  • Disaccharides –

• Polysaccharides ___

• Carbohydrates are polymerrs made up of monomers called monosaccharides (simple sugars).

  • Monosaccharides – simple sugars (ex. glucose & fructose_

  • Disaccharides – 2 Monosaccharides bonded together (ex. sucrose and lactose)

• Polysaccharides are complex carbohydrates; long chains of monosaccharides that are used to store energy (plants-starch and animals-glycogen) and to provide structure (cellulose).

• Proteins ____

• Functions:

• The chemical bond between amino acids are ____.

• Protein structure:

  • Primary Structure – ___

  • Secondary Structure – ____

  • Tertiary Structure – _____

  • Quaternary Structure – _____

    • Ex. _____

• Proteins are polymers made of monomers called amino acids.

• Functions: Structural, Regulatory, Contractile, Protective

• The chemical bond between amino acids is peptide bonds.

• Protein structure:

  • Primary Structure – the sequence of a chain of the amino acids

  • Secondary Structure – Hydrogen bonds folds the chain into “pleated sheets”

  • Tertiary Structure – Further folding to a 3-dimensional structure

  • Quaternary Structure – Sometimes more than one chain are put together, leading to a complex protein molecule

    • Ex. Hemoglobin (has four polypeptide chains).

• Lipids are ___

  • How would the molecules be described?

Examples:

• Triglycerides – ____

• Phospholipids – ___

• Steroids – ___

• Lipids are macromolecules made up of fatty acids

  • Nonpolar, hydrophobic molecules

Examples:

• Triglycerides – consists of 3 fatty acid chains and a glycerol.

• Phospholipids – consists of a polar phosphate group (head) and two nonpolar fatty acid chains (tails).

• Steroids – not made of fatty acid, but is hydrophobic, so is grouped as lipids.

Nucleic acids are ____

• Nucleic acids carry ___

• Can ___ itself.

Nucleotides are ___

• Made up of?

Example:

• DNA

  • Structure?

  • The sugar is ____.

  • Nitrogenous bases pairs are:

• RNA

  • Structure?

  • The sugar is ____.

  • Nitrogenous bases pairs are:

Nucleic acids (polymers) are made up of nucleotides (monomers)

• Nucleic acids carry the a cells’ instructions.

• Can replicate itself.

Nucleotides are made up of:

• Phosphate group

• 5-Carbon sugar

• Nitrogenous base

Example:

• DNA

  • A double-helix molecule that has antiparallel strands

  • The sugar is deoxyribose.

  • Nitrogenous bases include:

    • Adenine _(purine) - Thymine _(pyrimidine) (2 hydrogen bonds)

    • Cytosine _(pyrimidine) - Guanine _(purine) (3 hydrogen bonds)

• RNA

  • A single (stranded) helix molecule

  • The sugar is ribose

  • Nitrogenous bases include:

    • Adenine - Uracil

    • Cytosine - Guanine