Exam 1 study guide

What is a microorganism? What are some examples?

• Living organisms that are too small to be seen w/out magnification

• examples: Bacteria, archaea, protozoa, fungi, helminths, viruses, algae

Bacteria characteristics

• prokaryotic

• peptidoglycan cell wall

• unicellular

• asexual (by binary fission)

• circular DNA

• some autotrophic (photosynthesis) & some heterotrophic

Archaea characteristics

• prokaryotic

• pseudomurein cell wall

• unicellular

• asexual (binary fission)

• thermophiles (heat lovers)

• halophiles (salt lovers)

• methanogens (produce methane as a waste product of respiration)

• autotrophic and heterotrophic

• circular DNA

Fungi characteristics

• eukaryotic

• chitin cell wall

• heterotrophic

• unicellular (yeast) or multicellular (molds and mushrooms)

• sexual or asexual

• linear DNA

protozoa characteristics

• eukaryotic

• usually lacks cell wall

• heterotrophic

• unicellular

• sexual or asexual

• moves by: pseudopods (engulfs it), flagella (tall and long legs), cilia, some are non-mobile (not able to move)

Algae characteristics

• eukaryotic

• cellulose cell wall

• autotrophic (photosynthesis)

• unicellular or multicellular

• sexual or asexual

• often contain pigments like green, red, or brown

virus characteristics

• acellular (needs a host cell, not made of cells)

• obligate intracellular parasites

• DNA or RNA

• may be enveloped or naked

• has a capsid protein coat

• neither autotrophic/heterotrophic

helminths characteristics

• no cell wall

• heterotrophic

• sexual or asexual

• have microscopic stages (can eventually become large and carry diseases)

What makes viruses different from other microorganisms? for example, are viruses living and what is the structure of viruses

viruses are acellular and need a host cell in order to reproduce. They may be enveloped or naked. They have a capsid or a protein coat. They can either have DNA or RNA

What are helminths

flat worms and round worms (animal cells)

what does it mean to say that a microbe is ubiquitous

they are found everywhere on earth such as deep in earth’s crust, inside the bodies of plants and animals. Essential to life

genetic engineering

manipulates the genetic of microbes, plants, animals for the purpose of creating new products and GMOs

Recombinant DNA tech

makes it possible to transfer genetic material from one organism to another and deliberately alter DNA

bioremediation

uses microbes already present or introduced internationally to restore stability or clean up toxic pollutants

The term used to describe a disease-causing microorganism is

pathogen

What is the leading cause of infectious death in the US? what is the leading cause of infectious death in the world?

In the US< influenza and pneumonia. In the world, low respiratory system

taxonomy

the science of classifying living things

nomenclature

the assignment of scientific names to the various taxonomic categories and to individual organisms

classification

the orderly arrangement of organisms into a hierarchy

identification

the process of discovering and recording traits of organisms so that they can be placed in an overall taxonomic scheme

who developed the formal system for classifying and naming organisms

carolus linnaeus

each organism has 2 names. the first is the (1) and the second name is the (2)

1. genus

2. specific epithet/species

How are the names of organisms written

The genus is the first and the first letter is capitalized. The species is second and is lower cased. Both names are underlines (separately) or italicized (separately and if typed)

Carl Woese proposed that organisms may be classified into of one of three different domains by analysis of their

rRNA analysis

What are the three domains proposed by Carl Woese

Bacteria, archaea, and eukarya

How are organisms classified and organized into several descending ranks

• domain, kingdom, phylum/division, class, order, family, genus, species

• “Do Keep Pots Clean Or Family Gets Sick

who was the first to report that living things were composed of little boxes or “cells” from looking at the cork

Robert Hooke - invented the cell theory

cell theory

all living rhings are composed of cells and come from pre-existing cells

Who was the first to look at living microorganisms with a microscope

Anton van Leeuwenhoek (analyzed water and saw living things

Redi experiment

• sealed jar with decaying meat → no maggots; open jar w/out decaying meat → maggots

• supports biogenesis (life came form life)

Needham experiment

• broiled broth and then covered it w/ a cap → bacterial growth

• supports spontaneous generation (life came from nothing)

Spallanzan experiment

• covered broth and boiled it → no growth

• supports biogenesis, but fans say that boiling destroyed vital force

Pasteur experiment

• broth placed in s-shaped flask, heated, not sealed → no growth due to day and microorganisms trapped in bend

• supports biogenesis

pasteurization

application of gentle heat for a short amound of time

What are Koch’s postulates for? what are the steps for koch’s postulates

to determine whether or not an organism is pathogenic and which disease it caused

1. the same pathogen must be present in every case of the disease

2. the pathogen must be isolated from the diseased host and grown in pure culture

3. the pathogen from the pure culture must cause the disease when it is inoculated into a healthy, susceptible laboratory animal

4. the pathogen must be isolated from the inoculated animal and msut be shown to be the original organism

How did jenner produce the first vaccine

he found that milk maids were immune to smallpox due to being exposed to cowpox and cows. He would explore individuals to material from cowpox lesion (similar to smallpox). Then exposed them to smallpox and there’s no reaction

immunity

protection from disease provided by vaccination

what type of enzymes were discovered in the 1970s that is used to cut DNA in specific ways

restriction enzymes - molecular “scissors” inside bacteria → allow recombinant/genetic engineering and treatment for diseases

What technique was invented in the 1980s by Kary Mullis, that was awarded the Nobel Prize in 1993, that is used to amplify and subsequently analyze DNA

Polymerase Chain Reaction (PCR) - detect tiny amounts of DNA and make many copies of DNA. Method for discovering new organisms, diagnosing infectious diseases, and for forensic work

prokaryotic

has no nucleus

peptidoglycan

protein sugar wall

chitin

a fibrous substance consisting of polysaccharides and forming the major constituent in the exoskeleton of arthropods and the cell walls of fungi.

cellulose

an insoluble substance which is the main constituent of plant cell walls and of vegetable fibers such as cotton. It is a polysaccharide consisting of chains of glucose monomers.

photosynthesis

• light-fueled conversion of carbon dioxide to organic material

• accompanied by the formation of oxygen

anoxygenic photosynthesis

• occurred in bacteria before plants evolved

• did not produce oxygen as a byproduct

• more efficient in extracting energy from sunlight

oxygenic photosynthesis

• evolved from anoxygenic photosynthesis

• photosynthetic microorganisms are responsible for 70% of the earth’s photosynthesis

spontaneous generation

the hypothesis that living organisms arise from nonliving matter; a “vital force” forms life

biogenesis

the hypothesis that the living organisms arise from preexisting life

aseptic technique

techniques that prevent contamination by unwanted microorganisms. Invented by Louis Pasteur

Germ theory of disease

proved that bacteria cause disease

Koch

proved that microorganisms can cause disease

Lister

First to use disinfectants in surgical procedures

fleming

discovered penicillin (an antibiotic)

Semmelweis

advocated handwashing between patients

Human microbiome project (HMP)

studied the diverse microbial communities that live in and on the human body, and their roles in human health and disease

What is the term for anything that has mass and takes up space

matter; fundamental unit of matter is the atom

know the parts of the atom. Name which parts are positively charged, negatively charged, and neutral. Which parts are in the nucleus. Which part of the atom is involved in chemical bonding

• protons: + charge; in the nucleus

• neutral: neutral charge; in the nucleus

• electrons: - charge; involved in chemical bonding

What are elements? What defines an element?

Any substance that cannot be reduced to any simpler set of constituent substances. Defined by # of protons in its nucleus

Fluorine has 9 protons, 9 neutrons, and 9 electrons. What is fluorine’s atomic number and mass number

• atomic number: 9 = # of protons

• mass number: 9 + 9 = 18 → # of protons + neutrons in the nucleus

what are isotopes? what is it about carbon-12, carbon-13, and carbon-14 that makes makes them all carbon? what is different between carbon-14 and carbon-12

• same # of protons and electrons; different neutrons

• c-14 = 8 neutrons (unstable/radioactive isotope that gives off energy)

• c-12 = 6 neutrons

How many electrons in the first, second, and third electron shell. When is an atom stable

• first = 2 electrons

• second = 8 electrons

• third = 8 electrons

• an atom is stable when all valence electrons are filled. lowest energy state. atoms can share, donate, or recieve electrons

what are ions? How do you know if an atom is an ion

• an atom or molecule with an electrical charge resulting from gain/loss of electrons

• when an electron is lost, a positive charge (cation) results

• when on is gained, a negative charge (anion) results

covalent bond

atoms share one or more electrons

ionic bond

atoms lose and accept electrons from each other

hydrogen bond

a covalently lined hydrogen atom can react with an electronegative atom (like oxygen)

compound

a substance consisting of 2 or more different elements combined in a fixed ratio

molecule

a group of atoms bonded together, representing the smallest fundamental unit of a chemical compound that can take part in a chemical reaction.

Is NH3 molecule polar or nonpolar

polar b/c N has an unequal sharing of electrons (partial charges are created)

Is CH4 molecule polar or nonpolar

nonpolar b/c C has equal sharing of electrons (no partial charge)

Why does sodium and chloride form a bond?

Sodium has 11 protons and 11 electrons and chlorine has 17 protons and 17 electrons. So when they form an ionic bond, chlorine steals one electron from sodium to bond w/ one of their electrons, so, sodium loses 1 electron and becomes a cation and chlorine gains 1 electron and becomes an anion

What atoms do organic molecules always contain? What atom do inorganic molecules usually lack?

Carbon and hydrogen are always contained in organic molecules. Inorganic molecules usually lack hydrogen (and even carbon)

Why is water considered to be polar? in hydrogen bonding, what will the hydrogen of one water molecule bond with

It is polar because of difference in electronegativity. In hydrogen bonding, hydrogen bond between water molecules

What property of water allows water to be transported up a plant from the roots to the leaves

Adhesion allows water to defy gravity (water sticks together)

Water has a great capacity to absorb and retain heat. b/c of this, we say that water has a high

specific heat

specific heat

amount of energy required to raise the temperature of a substance by 1 C

What property of water allows life to live in water even when water freezes in colder climate

(ice is less dense than water) → water expands when frozen; h bonds are constantly forming and breaking; crystalline structures of ice holds the water in a ridged, less dense structure

solution

a completely homogenous mixture made of 2 or more substances

solute

substance is dissolved

solvent

he substance in which something is dissolved

when you add salt to water and the salt dissolves, what is the salt called

solute

what makes a compound hydrophobic

substances that repel water; substances can’t h-bond with water and nonpolar and non-ionic (vegetable oil)

What makes a compound hydrophilic

substances that h-bond with water; ionic compounds: salt; polar molecules: sucrose

acid

• substances that release H+ in solution and increase H+ concentration

• ex: lemon juice

base

• substances that release OH- in solution and decrease H+ concentration

• ex: household bleach

If an acid is added to water, will the pH of the solution increase or decrease? Why?

It will decease because the solution will have more H+

If a base is added to water, will the ph of the solution increase or decrease? Also, what happens to the hydroxide ion concentration as a result of a base being added?

It will increase because the solution will have less H+

What is a buffer and how does it work (ie. what happens when H+ is depleted or in excess)

• a solution that resists change in pH

• If H+ is depleted, buffers donate H+

• If H+ is in excess, buffers accept H+

Chemistry

study of interactions between atoms and molecules

trace elements

life requires 25 essential elements such as iron, oxygen, carbon, hydrogen, nitrogen, etc.

outer shell is called

valence shell

outer electrons are called

valence electrons

chemical bonds

attractions between atoms

single covalent bond

the sharing of one pair of valence electrons

double covalent bond

the sharing of two pairs of valence electrons

highly electronegative atoms

• have a high attraction for electrons

• outer shells are nearly full

• oxygen, nitrogen, and chlorine are very electronegative

Atoms with very little electronegativity

• have a very low attraction for electrons

• outer shells are nearly empty

• hydrogen, carbon, and sodium are not very electronegative

ionic bond

when attraction holds te ions together. two ions w/ opposite charges attract each other

chemical reactions

making or breaking of bonds between atoms

Chemical energy

the potential energy stored within the chemical bonds of atoms and molecules. This change occurs during a chemical reaction