Human Microbiology Exam 2
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Human Microbiology Exam 2
What is the structure of an atom?
Neutrons (no charge)
Determine what the atom is, atomic number
Determine how the atom reacts chemically
impart little bioogical importance
Neutrons + protons = atomic weight.
Are atoms electrically neutral?
Yes, the total positive charge of the nucleus = the total negative charge of the electrons.
Shells can hold a specific number of electrons
: 2, 8, 8, 18, 18, ect
If the outer shell is full the element is nonreactive or inert
If the outer shell is not full the element is reactive
There are 92 naturally occuring elements.
26 commonly found in living things.
Elements of Life
Element Symbol Atomic # Atomic Weight
Hydrogen H 1 1
Carbon C 6 12
Nitogen N 7 14
Oxygen O 8 16
Sodium Na 11 23
Magnesium Mg 12 24
Phosphorus P 15 31
Sulfur S 16 32
Chlorine Cl 17 35
Potassium K 19 39
Calcium Ca 20 40
Iron Fe 26 56
Iodine I 53 127
Atoms interact with each other in a certain combination to form molecules
number of protons in nucleus
Total number of protons and neutrons in an atom
All atoms with the same number of protons
The arrangement of electron shells corresponding to different energy levels
When is an atom stable or inert?
When the outer shell is filled
"Combining capacity" of an atom is the number of extra or missing electrons in its outermot shell
A molecule that contains at least 2 different kinds of atoms
The attractive force that combines molecules and holds them together.
When atom gains electrons is acquires an overall negative charge If it loses electrons it gains an overall positive charge. Negatively or positively charged atom (or group of atoms) called ions.
an attraction between ions of opposite charges that hold them together to form a stable molecule.
An atoms whose outer electron shell is less than half filled will lose electrons and form positively charged ions
An atom whose outer is more than half-filled and gains electron
atoms share one or more electrons
Hydrogen is interacting with other hydrogen, nitrogen, and oxygen. Weaker than covalent and ionic bonds. 5% of strength of covalent bonds.
two or more atoms , ions, or molecules combine to form new and larger molecules can go both ways.
Amount of hydrogen ions in a solution. Hydrogen makes things acidic. Scale 0-14 lower more acidic, higher more basic. Extremes will cause denaturing of proteins.
is a polar molecule. Universal solvent.
compounds that keep the pH the same. Keep the pH stable.
Building blocks of proteins
Toxic Shock Syndrome
bacteria, bacillus, cocci, spiral
Peptidoglycan is found in cell walls not eukaryotes
multiply by binary fission
ability of bacteria to survive in enviroment.
tail-like structure that helps bacteria move.
flagella all over cell
How do flagella attached to G+ and G- bacteria
Gram+ positive stain thin wall
Gram- negative stain thick wall peptidoglycan
In both the flagella attach through hook and spindle to the cell wall
helps to attach to the host cells
peptidoglycan layer consists of two primary sugars
NAM- acetylmuramic acid
linked by 10-65 sugars polypetides
many fat sugars
movement from higher to lower concentration. passive process
Passive process. Proteins
Water follows salt movement of solvent molecules Must have semi permeable membrane
High salt content water will flow inside cell.
Low salt content
no net movement
The cell uses energy in the form of ATP to move substances across the plasma membrane. Usually from outside to inside.
Ex: Ions, amino acids, simple sugars.
Interferes with peptidoglycan synthesis
Bacterial species are differentiated by
morphology, chemical composition, nutritional requirements, biochemical activities and source of energy.
LPS cell communication
Membrane Proteins- Fluid Mosaic Model
Model that describes the plasma membrane that allows things in and out cells
rupturing of the cell
Does not pass through cell wall without aid from protein
Think penis...used in exchange of DNA
Rough- has Ribosomes?
Smaller cell engulfed by larger cell. mutually beneficial relationship.
Synthesis A+B= AB
Decomposition AB= A+B
Water Hydrogen bonding
Polar both positive and negative.
Disassociation of salt in water.
Three basic building blocks
backbone of DNA phosphates
Where lysosomes are formed. 3-20 cisterns that aid in the modification of glycoproteins, glycolipids, and lipoproteins
Central in the production of ATP.