Chapter 2 & 3 Flashcards
(T/F) All living organisms contain molecules with carbon (C).
True.
What makes a molecule organic?
A molecule is considered organic if it contains carbon (C) and hydrogen (H) atoms.
(T/F) Atoms are the smallest unit of matter.
True.
What are the three subatomic particles that atoms are composed of?
- Protons are positively charged
- Electrons are negatively charged
- Neutrons are uncharged
protons + #neutrons =
protons + # neutrons = atomic mass
protons =
protons = atomic number
Define: Isotopes
Each of two or more forms of the same element that contain equal numbers of protons but different numbers of neutrons in their nuclei, and hence differ in relative atomic mass but not in chemical properties; in particular, a radioactive form of an element.
Define: Radioisotopes
Radioisotope (also known as radisotope) These are radioactive isotopes, since they have an unstable atomic nucleus (due to the balance between neutrons and protons) and emit energy and particles when it changes to a more stable form.
(T/F) The number and arrangement of electrons determines if atoms will interact.
True.
Define: Elements
An element is a substance that cannot be broken down into other substances by chemical reactions. All the elements are listed on the periodic table.
Describe the anatomy of an atom.
Electrons are attracted to the positively charged nucleus but repel one another. The number and arrangement of electrons determines if atoms will interact. Electrons move in electron shells (volumes of space that surround the nucleus).
Define: Chemical Bonds
A chemical bond is a union between electron structures of atoms. Atoms bond to form molecules
Define: Molecule
The smallest part of a compound that displays the properties of that compound.
Define: Compound
A substance whose molecules contains two or more different atoms bonded together (H2O).
Define: Covalent Bond
A bond that forms when two atoms share a pair of electrons. Covalent bonds are the strongest bond in living organisms. When atoms share electrons unequally, it is called a polar covalent bond (i.e. water).
Define: Ionic Bond
Ionic bonding is the complete transfer of valence electron(s) between atoms. It is a type of chemical bondthat generates two oppositely charged ions. In ionic bonds, the metal loses electrons to become a positively charged cation, whereas the nonmetal accepts those electrons to become a negatively charged an ion.
Define: Hydrogen Bond
A hydrogen bond is an attraction between hydrogen and oxygen. The attraction between two neighboring water molecules is a hydrogen bond. Hydrogen bonds form because each water molecule exhibits polarity (being positive or negatively charged).
Define: Acid
A chemical substance that donates H+ when dissolved in water. Acids have higher H+ concentration.
Acidic solutions have pH < 7
Define: Base
A chemical substance that accepts H+ when dissolved in water.
Basic or alkaline solutions have pH > 7
Define: Dehydration Synthesis
The monomers combine with each other via covalent bonds to form larger molecules known as polymers. In doing so, monomers release water molecules as byproducts. This type of reaction is known as dehydration synthesis, which means “to put together while losing water.”
Dehydration means to remove water.
Synthesis means to build.
What is a triglyceride?
Triglycerides (fats) are a molecule consisting of one glycerol and three fatty acids.
What is a phospholipid?
A phospholipid has two fatty acid tails and a phosphate/glycerol head. The head is hydrophilic and the tails are hydrophobic.
Describe the structure of a primary protein.
A linear sequence of amino acids.
Describe the structure of a secondary protein.
A double helix.
Describe the structure of a tertiary protein.
Folded 3-D structure which determines the function.
Confirmation (structure) of protein determines function.
“Mess”.
Describe the structure of a quarternary protein.
Some proteins are made up of more than one polypeptide chain.
i.e. enzymes.
