Chemistry Review Flashcards
What is the difference between mass and weight?
The mass of an object relates to the actual amount of matter in the object and remains constant wherever the object is. Weight varies with gravity.
What is the most useful form of energy for living systems?
Chemical energy - it runs almost all biological processes
What does the body use electrical energy for?
Nerve impulses, heart contractions
What four elements make up 96% of the human body?
Carbon, hydrogen, oxygen, and nitrogen
What are the 9 lesser elements of the body?
Calcium, phosphorus, potassium, sulfur, sodium, chlorine, magnesium, iodine, and iron
What is the atomic number?
Number of protons in the nucleus
How does the orbital model of the atom depict it?
As denser shading showing probable regions of greatest electron density surrounding the nucleus
What is the mass number?
The sum of the masses of protons and neutrons in an element
How do you calculate the number of neutrons in an atom?
Mass number - atomic number
What is the atomic number?
The number of protons in an element
What is atomic weight?
An average of the weights of all isotopes of an element, taking into account their relative abundance
What is a homogeneous mixture of components that may be gases, liquids, or solids?
Solution
What are some characteristics of a solution?
Tiny solute particles that do not scatter light or settle out, exactly the same composition throughout
What is a mole?
A mole of any element is equal to its atomic weight; a mole of a compound is equal to the combined atomic weights of its constituents
What is Avogadro’s number?
1 mole of any substance always contains 6.02 x 10^23 number of solute particles
How would you create a 1.0 M solution of glucose?
Add up the atomic weights of its constituents and set that equal to 1 mole. Subtract that number from 1000ml and add an equivalent amount of water to 1 mole of glucose.
What is a heterogeneous mixture in which solute particles are larger than in a solution and scatter light but do not settle out?
Colloid
What type of mixture can undergo a reversible sol-gel transformation?
Colloid
What is another word for a colloid?
Emulsion
What is a heterogeneous mixture with very large solute particles that settle out and may scatter light?
Suspension
Is blood a solution, colloid, or suspension?
Suspension
Is cytosol a solution, colloid, or suspension?
Colloid
What are some differences between a mixture and a compound?
No chemical bonding occurs between components of a mixture. Mixtures can be separated by physical means, but compounds can only be separated by chemical means.
In an oxidation-reduction reaction, the reactant losing the electron is the _____ and is ________.
Donor; oxidized
In an oxidation-reduction reaction, the reactant gaining the electron is the ______ and is said to be ________.
Acceptor; reduced
A substance is __________ either by losing hydrogen atoms or by combining with _________.
Oxidized; oxygen
Not all redox reactions involve the __________ transfer of electrons. Some just change the pattern of electron sharing in _______ ______.
complete; covalent bonds
What is the difference between a covalent bond and an ionic bond?
An electron is completely transferred from one component to another in an ionic bond. In a covalent bond, at least one pair of electrons is shared among the two components.
What kind of reaction releases energy and has products that are less energetic than the initial reactants? What are some examples of this type of reaction?
Exergonic reactions; catabolic reactions and oxidative-reduction reactions
What type of reaction contains more potential energy in its products than the initial reactants did? What are is an example?
Endergonic; anabolic reactions, dehydration synthesis
What percentage of living cells is made up of water?
60 to 80%
How does water help with homeostasis?
It has a high heat capacity and a high heat of vaporization, making it able to help regulate body temperature by redistributing heat among body tissues and via sweating.
What property of water allows it to form biological colloids?
Its ability to form hydration layers around large molecules, such as proteins, to prevent them from settling out of the solution
What are groups of atoms that bear an overall charge called?
Polyatomic ions
What are electrolytes?
Substances that conduct electricity in solution
What are electrolytes essential for in the body?
Conducting nerve impulses, muscle contractility, and assisting with chemical reactions
What is the equation for calculating pH?
pH = -log[H+]
What is a buffer system? What compound acts as a buffer in blood?
A buffer is a combination of a weak acid and a weak base that helps prevent big changes in pH by taking up H+ if pH is dropping and donating H+ if pH is rising. The bicarbonate buffer system does this in blood.
What is the normal pH range for blood?
7.35 to 7.45
What is hydrolysis?
Water is added to a compound to break it down
Sucrose + H2O -> Glucose and Fructose
What is a dehydration synthesis?
Hydrogen is lost from one reactant and a hydroxyl ion is lost from the other so that they may join. Water is released.
What is the general chemical formula of a carbohydrate?
(CH2O)n
What are the three disaccharides?
Lactose, maltose, and sucrose
What is lactose composed of?
Glucose and galactose
What is sucrose composed of?
Glucose and fructose
What is maltose composed of?
Two glucose molecules
What lipid molecules play a role in various body processes including blood clotting, regulation of blood pressure, inflammation, and labor contractions?
Prostaglandins
What molecules do NSAIDs block the action of?
Prostaglandins
How is an alpha helix formed?
Via hydrogen bonds between NH and CO groups in amino acids in the same primary chain, about 4 amino acids apart
What chemical bonds are important in the formation of tertiary protein structure?
The protein folds so that the hydrophobic R groups move to the inside and hydrophilic R groups move to the outside. These hydrophobic interactions are reinforced by covalent and hydrogen bonding.
What are the two types of proteins?
Fibrous and globular
Which protein type is known as a structural protein? What is an example?
Fibrous proteins; collagen
What type of proteins are considered the functional proteins? What are some examples?
Globular proteins; antibodies, enzymes, protein-based hormones
What does the holoenzyme consist of?
Apoenzyme (the protein portion) and a cofactor
What are typical cofactors?
Ions of a metal element such as copper or iron; vitamins, especially B vitamins
What is a coenzyme?
An organic cofactor, such as a B vitamin
What is the substance that an enzyme acts on called?
Substrate
