15Chapter 2: Introduction to Chemistry Flashcards
All living and non-living things consist of _______.
Matter
List the 4 elements that make up about 96% of our body weight.
- Carbon
- Nitrogen
- Hydrogen
- Oxygen
What elements are S, Na, Mg, and Fe?
Sulfur
Sodium
Magnesium
Iron
What are the symbols for Potassium, Chlorine, Hydrogen?
K, Cl, H, C
Isotope
Atoms of the same element that differ slightly in mass.
Radioactive Isotope
An isotope that is unstable and emits radiation (energy) as it breaks down.
Electrolyte
An ionic compound (salt, acid, or base) that beaks apart into cations and anions when dissolved.
– conducts electric current.
What kind of charges are carried by cations and anions?
Cation= positive charge Anion= negative charge
Ionic bond *give example
Positively charged ions that are attracted to one another (weak bond)
example= sodium chloride (table salt)
Covalent Bond *give example
When atoms form a molecule by sharing one, two, or three pairs of their outer shell electrons
example: hydrogen (H2), oxygen (O2), methane (CH4), and water(H2O)
What is the pH of blood?
7.35-7.45
The atoms of the isotopes of a particular element vary in their number of __________.
Neutrons
Which element is needed for clotting and muscle contraction, and contributes to the hardness of teeth and bone?
calcium
What type of bonds hold water molecules together?
covalent bonds
The more _______ ions present in a solution, the more basic the solution.
Hydrogen
An acid is a substance that dissociates in H2O into one or more _______ ions and one or more _______.
Hydrogen / anions
Organic compounds always contain?
Hydrogen and carbon
The most plentiful lipid in the human body is ________.
Triglyceride
“Saturated fat” is saturated with what?
Hydrogen
Steroids are classifies as ______.
Lipids
In RNA, the base that is present instead of thymine is ________.
Uracil
ATP belongs to the category of compounds known as what?
Nucleic Acids
How is ATP the “energy currency” of the cell?
ATP releases energy stored in its 2 high-energy phosphate bonds.
How does RNA differ from DNA chemically and physically?
Chemically: RNA nucleotides are made up of the sugar ribose, DNA nucleotides are made up of deoxyribose. Physically: RNA is single-stranded, DNA is double-stranded. RNA uses uracil while DNA uses thymine.
Structure of DNA
DNA is a large molecule consisting of two helically wound chains of nucleotides.
The two chains are held together by hydrogen bonding between the nitrogenous base pairs
-Adenine and thymine (A,T)
-Cytosin and granine (C,G)
Nucleotides
Building blocks of nucleic acids.
Made up of a nitrogen base, a pentose sugar, and one or more phosphate groups.
What is the function of an enzyme?
Enzymes are biological catalysts that have specufic “active” binding rates for certain substrates. Enzymes low energy of activation so that reactions in cell can occur at appropriate rate.
What are the 4 chemical groups of an amino acid?
- hydrogen
- an amine
- a carboxyl
- a side chain (R group)
What are the 3 important types of lipid and their functions?
- Triglycerides - energy storage
- Phospholipids - membrane structure
- Steroids - hormone membrane structure
Lipids
Include most of the substances that are insoluble in H2O but soluble in non-polar solvents such as chloroform or ether.
Monosaccharides *give example
Simple sugars made up of C, H, and O.
examples= glucose, fructose, and deoxyribose
Buffer
Combination of chemicals that minimizes changes in the pH of a solution when acids and bases are added.
pH
A measure of the hydrogen ion concentration of a solution.
Salt *when added to water
When put into water, a salt is a substance that dissociates into cations and anions neither of which is (H+) or (OH-)
example = sodium chloride
Base *when added to water
When put into water, a base is a substance that dissociates into hydroxide (OH-) ions and one or more cations.
Also can be descrided as having the capacity to pick up one or more hydrogen (H+) ions.
Acid *when added to water
When put into water, an acid is a substance that dissociates into hydrogen ions and one or more anions.
Hydrogen Bond
Extremely weak bonds between 2 atoms
- important for giving proteins and enzymes their 3-dimensional shapes, bonding specialized molecules such as hormones and receptors, and for binding enzymes to substrates.
A substance that ____ is considered to be a chemical compound.
Has covalent bonds
When is a ionic bond formed?
two cations meet
The ionization of a sodium atom to produce Na+ is an example of what?
anabolism
A substance capable of dissolving freely in water is _____.
amphipathic
How is a carboxyl group symbolized?
-COOH
What is that only polysaccharide synthesized in the human body?
glycogen
What it the arrangement of a polypeptide into a fibrous or globular shape called?
tertiary structure
The feature that most distinguishes a lipid from a carbohydrate is that a lipid has _____________.
a lower ratio of oxygen to hydrogen
