Ch.2 Test Flashcards
The smallest basic unit of matter
Atom
Name subatomic particles and their charges
Proton-Positive
Neutron-Neutral
Electron-Negative
What two subatomic particles are in the nucleus of an atom?
Protons and neutrons
Electrons in the outer ring of an element that are involved in bonding and give an atom its properties
Valence electrons
What does the atomic number tell us about an atom?
The number of protons and electrons
What does the atomic mass tell us about an atom?
The number of neutrons by subtracting the atomic number from the atomic mass
Atoms of the same element that differ in the number of neutrons they contain
Isotopes
Why do isotopes still have the same properties as regular atoms?
Electrons are responsible for their properties and because their number of electrons does not change, neither does their properties
A _____ is made of different elements bonded together.
compound
When do ions form?
When atoms gain or lose electrons
What is an ion?
An atom that has gained or lost one or more electrons
A positive ion has gained/lost electrons
lost
A negative ion has gained/lost electrons
gained
____ bonds form between oppositely charges ions
Ionic
_____ bonds forms when atoms share a pair of electrons
Covalent
When 2 or more atoms are held together by covalent bonds, they are referred to as a ______
molecule
What are the properties of water?
Cohesion, adhesion, less dense when solid, expands when it freezes, high specific heat, polar, forms hydrogen bonds, universal solvent
_____ bonds form between slightly positive and slightly negative atoms
Hydrogen
Unequal distribution of charge; unequal pull of electrons that the molecule shares
Polarity
What is high specific heat?
Water can resist temperature changes. This is important for maintaining homeostasis
What is cohesion?
Water molecules can stick to other water molecules
What is adhesion?
Water molecules can stick to other things
What is capillary action?
Tendency of water to be drawn up a narrow tube
_____ is formed when one substance dissolves in another
A solution
The substance that is present in the greater amount, dissolves the other
Solvent
The substance that dissolves in the other substance
Solute
What does pH stand for>
Power of hydrogen
On the pH scale, what number is neutral?
7
Numbers above 7 are _______
Bases
Numbers below 7 are _______
Acids
The farther away you get from 7 (either direction), the ____ the acid or base gets
Stronger
Acids form ____ ions
H+
Bases from ___ ions
H-
Acids have a ____ taste
sour (think of lemon)
Bases have a _____ taste
bitter (think of B for bitter)
Weak acids or bases that can react with strong acids or bases to prevent sudden changed in pH
Buffers
What are the 4 major macromolecules of life?
Carbohydrates, lipids, proteins, nucleic acid
What are carbohydrates composed of?
Carbon, hydrogen, oxygen
What is the function of carbohydrates?
Break down to provide energy (ATP)
What are the monomers of carbohydrates?
Simple sugars (glucose)
What are lipids composed of?
Carbon, hydrogen, and a little oxygen
What is the function of lipids?
Plan B for energy, create hormones and cell membranes
What are some examples of lipids?
Fats, oils, cholesterol
Phospholipids make up ___ _____
cell membranes
The head of a phospholipid is ____ or ____ _____
hydrophilic; water loving
The tail of a phospholipid is ______ or _____ _____
hydrophobic or water fearing
What are proteins composed of?
Carbon, hydrogen, oxygen, nitrogen
What are the monomers of proteins?
Amino acids
What is the function of proteins?
They change the rate of a chemical reaction by lowering activation energy
Proteins that change the rate of a chemical reaction by lowering activation energy are called…
Enzymes
Proteins differ in the number and order of ____ _____
amino acids
What are nucleic acids composed of?
Carbon, hydrogen, oxygen, nitrogen, phosphorus
What are the monomers of nucleic acids?
Nucleotides
What are the 3 parts of a nucleotide?
Sugar, phosphorus, nitrogenous base
What are 2 examples of nucleic acids?
DNA and RNA
What is the function of nucleic acids?
DNA-store genetic information
RNA-makes proteins
What are the 4 forms of energy?
Chemical, electrical, thermal, mechanical
Change substances into different ones by breaking and forming chemical bonds
Chemical reaction
What are the 2 parts of a chemical reaction?
Reactants and products
Change during a chemical reaction
reactants
Made during a chemical reaction
products
Energy is _____ to break a bond
added
Energy is ____ when bonds form
released
The amount of energy that needs to be absorbed to start a chemical reaction
Activation energy
Release more energy than they absorb
Exothermic reactions. On graph, total energy released is below the starting amount
Absorb more energy than they release
Endothermic reactions. On graph, total energy released is above starting amount
Enzyme is a a _____
Catalyst
Speeds up the rate of a chemical reaction by lowering the activation energy
Catalyst
Disruption of _____ can interrupt enzyme function
homeostasis
Change in temperature or pH would _____ and not allow it to function
break the hydrogen bonds
