Microbiology Chapter 2 Flashcards
Structure of the Atom
The basic structure of an atom is a nucleus, containing at least one proton and usually one or more neutrons. protons have slightly less mass than the neutrons and are positively charged. neutrons have the greatest mass and have no charge.
Outside of the nucleus contain one or more electrons. The energy levels are often called rings. The electrons have almost no mass and are negatively charged. The electrons move around the nucleus in energy levels.
Ionic Bond
type of linkage formed from the electrostatic attraction between oppositely charged ions in a chemical compound.
Covalent Bond
A covalent bond is a chemical bond that involves the sharing of electrons to form electron pairs between atoms.
Hydrogen Bond
a weak bond between two molecules resulting from an electrostatic attraction between a proton in one molecule and an electronegative atom in the other.
Synthesis Reaction
Synthesis reaction: A + B –> AB
Decomposition Reaction
AB –> A + B
Exchange Reaction
AB + CD –> AD + BC
Polar Covalent Bond
Occurs when atoms are shared unequally in a covalent bond. Specifically, when the difference in electronegativities of the two atoms in the bond is between 0.4 and 1.7.
What do polar bonds have to do with hydrogen bonding?
Hydrogen bonds are polar because the hydrogen and the electronegative atom do not share electrons equally.
Acid
They are chemical compounds which yield hydrogen ions or protons when dissolved in water, whose hydrogen can be replaced by metals or basic radicals, or which react with bases to form salts and water (neutralization).
Base
The nucleobase of a nucleotide involved in base pairing, as of a DNA or RNA polymer.
Buffer
a solution containing either a weak acid and its salt or a weak base and its salt, which is resistant to changes in pH.
pH
Power of Hydrogen
quantitative measure of the acidity or basicity of aqueous or other liquid solutions.
Describe the relative amounts of H+ and OH- in an acid, base, and neutral solution. Where would each type of solution fall on the pH scale?
Acid: Below the pH of 7, high number of hydrogen concentration and low number of OH- concentration.
Neutral: pH of 7 (blood, water). Has the same amount of concentration of H+ and OH- concentrations
Base: Above pH of 7, low number of hydrogen concentration and low number of OH- concentration
For one number change in pH, there is a change in acidity by 10 times.
Organic Compound
any of a large class of chemical compounds in which one or more atoms of carbon are covalently linked to atoms of other elements, most commonly hydrogen, oxygen, or nitrogen.
Inorganic Compound
any substance in which two or more chemical elements (usually other than carbon) are combined, nearly always in definite proportions.
Organic
denoting a relation between elements of something such that they fit together harmoniously as necessary parts of a whole.
Identify the building blocks of
carbohydrates.
Monosaccharides include glucose, galactose and fructose - all commonly found in food. Monosaccharides are single sugar molecules that are the building blocks for all other sugars and carbohydrates.
Give an example of a monosaccharide, a disaccharide, and a polysaccharide
monosaccharide: glucose (dextrose), fructose, galactose, xylose and ribose
Disaccharide: Sucrose (common table sugar)
Polysaccharide: Cellulose and Starch
Simple Lipid
These consist of long chain fatty acids which may be either free or combined with an alcohol by an ester linkage. They include the triglycerides (triacylglycerols) and the waxes.
Complex Lipids
Complex lipids can be defined as heterogeneous compounds made up of steroids, fats, waxes, oil, and other substances.
Heterogenous Compound
A heterogeneous mixture consists of substances which remain physically separate. It can easily be separated into its constituents by processes such as filtering, hand picking, magnetic separation etc. Example- a mixture of sand and marble.
Steroids
Steroid hormones are cyclical chemical compounds made up of rings of carbon atoms that play an essential role in a wide range of physiological functions, including growth, development, energy metabolism, homeostasis and reproduction.
How do simple lipids differ from complex lipids?
Simple lipids contain just two types of components: fatty acids and alcohols. 2. Complex lipids contain more than two types of components: other components in addition to the fatty acids and alcohols.
Identify the building blocks and structure
of proteins.
The building blocks of proteins are amino acids, which are small organic molecules that consist of an alpha (central) carbon atom linked to an amino group, a carboxyl group, a hydrogen atom, and a variable component called a side chain
Describe the reactions that are used to build and break down proteins
Dehydration synthesis reactions build molecules up and generally require energy, while hydrolysis reactions break molecules down and generally release energy.
Identify the building blocks of nucleic
acids.
A nucleotide is the basic building block of nucleic acids (RNA and DNA). A nucleotide consists of a sugar molecule (either ribose in RNA or deoxyribose in DNA) attached to a phosphate group and a nitrogen-containing base.
Describe the role of ATP in cellular
activities.
ATP is able to power cellular processes by transferring a phosphate group to another molecule (a process called phosphorylation). This transfer is carried out by special enzymes that couple the release of energy from ATP to cellular activities that require energy.
Which can provide more energy for a cell and why: ATP or ADP?
ATP (adenosine triphosphate) stores more energy than ADP (adenosine diphosphate). ATP has three phosphate groups with high energy bonds located between each group. ADP has only two phosphate groups.
What is the smallest component of a substance that CANNOT be divided into smaller substances without losing its properties?
Element
Atoms with different numbers of neutrons in their nuclei are called:
Isotopes
Which type of bond is weak and does NOT bind atoms into molecules?
Hydrogen Bond
A bond formed from the attraction between ions of opposite charge is called a(n):
Ionic Bond
Water has an unequal distribution of charges and is called a(n):
Polar Molecule
A compound that helps keep the pH from changing drastically is:
A Buffer
MOST microbes grow best at a pH from:
6.5-8.5
In a decomposition reaction, sucrose can be broken down into:
Glucose and Fructose
The following is an example of what type of reaction?
AB + CD –> AD + BC
Exchange Reaction
Endergonic reactions ALWAYS:
Absorb more energy than they release
ex. photosynthesis
In a synthesis reaction,
atoms, ions, or molecules are combined to form a larger molecule
Which of the following are the “building blocks” (monomers) of peptides?
Amino Acids
Which of the following nitrogenous bases is NOT found in an RNA molecule?
Thyamine
Why do saturated fats become solid more easily than unsaturated fats?
They are straight chains and pack more tightly together
Glycogen, chitin, and cellulose are examples of:
Polysaccharides
Which of the following is the type of bond holding K+ and I- together in KI?
Ionic Bond
Identify the following reaction: Lactose + H2O → Glucose + Galactose.
Hydrolysis Reaction
Which type of molecule is composed of (CH2O) units?
Carbohydrates
ATP is a(n):
Nucleotide
In a cell, phosphorous would most likely be found in:
Plasma Membrane
Fill-in-the blank: Carbohydrates are made up of carbon, hydrogen, and oxygen with the ratio of hydrogen to oxygen atoms being _______________. Type your answer using the format A:B.
2:1
An abundant polysaccharide that is found in plant (and some algal) cell walls is _______________.
Cellulose
Peptidoglycan is found only in:
bacteria
A single phospholipid molecule is best described as:
Amphipathic
Amphipathic
having both hydrophilic and hydrophobic parts.
Some bacteria make proteins that can causes disease in humans. These proteins are called:
Exotoxins
