Bio 100 Study Guide for Exam 1 PDF

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Cellular Organization, Cells, Evolution, Types of Cells, Atoms...

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Study Guide for Exam #1 Lecture Topic 1 1) List and be able to discuss the major and most significant characteristics shared by all living things. ● 1. Order/ Cellular Organization ○ Subatomic particles (protons, neutrons, electrons) → Atoms → Molecules & Macromolecules → THE CELL! (All the non-living/raw materials organized= the cell) ○ 2 General types of cells: ■ 1. Prokaryotic Cells: Simplistic, smaller than eukaryotic cells, they have NO ORGANELLES (internal compartments) ● PRO: 1st, before ● KARY: Nucleus, center ■ 2. Eukaryotic Cells: They have a nucleus and other organelles ● EU: True, real ● KARY: Nucleus, center ○ Minimum Requirements for a cell: ■ 1. Cell Membrane (Plasma Membrane) “mmb” ■ 2. DNA (genetic blueprint/ info) ■ 3. Cytoplasm: Liquid gel-like substance with dissolved “goodies” ○ Other parts of a cell: ■ Lysosome: “stomach” ● LYSE: Split apart/ digest ● SOME: Body ■ Nucleus: “brain” ■ Mitochondria: “engine” powerhouse of the cell. ● Most of the energy in the form of ATP is generated here from the breakdown of food ○ Cells → Tissues → Organs → Organ Systems → Multicellular Organism → Population → Community → Ecosystem (community and surrounding environment) → Biosphere (Earth) ● 2. Metabolism (Energy Processing) ○ Energy: The ability to perform work ○ Metabolism: The sum total of all the chemical reactions going on that are related to energy processing. ■ Catabolic Reactions: Break Down/ Digestive Reactions-- Energy releasing ( breaking down your food and releasing the energy) ● MCue: Catastrophic= Destroy  eactions/ Synthesis-- Energy absorbing reactions ■ Anabolic Reactions: Build up R (Muscles/ fat) ● 3. Reproduction, Growth, Development ○ DNA: Deoxyribonucleic Acid (our genetic blueprint) ■ DNA → Gene: Segment of DNA that codes for protein →(transcription[copying])→ RNA: sister of DNA - a strand of DNA →(translation) → Protein → Traits (eye color, etc) ● 4. Ability to Sense, Respond, and Regulate ○ Homeostasis: the ability to maintain an internal “constancy” even as the external environment changes ● 5. Evolutionary Adaptation

Evolution: to change or diversify over long periods of time/ change in the allele frequency of specific genes ● Alleles: different versions of specific genes ■ Inherited changes that build on each other ○ In order for evolution to occur, you need: ■ 1. Genetic variety must be present ■ 2. Driving “force” to change the frequency of alleles ● Ex: Further mutations, migration, natural selection, etc. 6. Death ○ Prevents crowding, makes resources last, decomposition back to the raw materials ■ Decomposers: Break down dead organisms. They absorb what they need and let back out what they don’t need ○

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2) Define and discuss the terms energy, metabolism, anabolic and catabolic reactions, homeostasis, evolution, and decomposers. (EVERYTHING IS LISTED ABOVE TOO) ● Energy: The ability to perform work ● Metabolism: The sum total of all the chemical reactions going on that are related to energy processing. ○ Catabolic Reactions: Break Down/ Digestive Reactions-- Energy releasing ( breaking down your food and releasing the energy) ■ MCue: Catastrophic= Destroy  eactions/ Synthesis-- Energy absorbing reactions (Muscles/ fat) ○ Anabolic Reactions: Build up R ● Homeostasis: the ability to maintain an internal “constancy” even as the external environment changes ● Evolution: to change or diversify over long periods of time/ change in the allele frequency of specific genes ● Decomposers: Break down dead organisms. They absorb what they need and let back out what they don’t need 3) List, in order, the levels of organization found in living things from subatomic particles to the biosphere, and provide a one-sentence definition for the terms: organelle, cell, population, community, ecosystem, and biosphere. (EVERYTHING IS LISTED ABOVE TOO) ● Subatomic particles (protons, neutrons, electrons) → Atoms → Molecules & Macromolecules → Cell → Tissues → Organs → Organ Systems → Multicellular Organism → Population → Community → Ecosystem → Biosphere ● Organelle: internal compartments within a cell ● Cell: All the non-living/raw materials organized ● Population: A collection of the same species ● Community: Various populations in the same area ● Ecosystem: community and surrounding environment ● Biosphere: Earth 4) What is the most significant difference between prokaryotic and eukaryotic cells? What does "kary" mean? (EVERYTHING IS LISTED ABOVE TOO) ● 1. Prokaryotic Cells: Simplistic, smaller than eukaryotic cells, they have NO ORGANELLES (internal compartments) ○ PRO: 1st, before ○ KARY: Nucleus, center ● 2. Eukaryotic Cells: They have a nucleus and other organelles ○ EU: True, real

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KARY: Nucleus, center

5) When do scientists believe the Earth was formed (how old is it)? When do scientists believe life began On Earth? What is a mass extinction? How many have we had to date? ● How Old? ○ Approx. 4.5 billion years old ● Life Began? ○ Approx. 3.5 to 4 billion years ago (it took them about .5 to 1 to begin) ● Mass Extinction: When a huge number of species die off at a rapid pace ● How mass Mass Extinctions? ○ Approx. 5 ■ The last one was the dinosaurs with the meteor and the dust cloud ● OTHER NOTES: ○ Normal rate of extinction? Approx. 100 species/year ○ Current rate of extinction? Approx. 30,000 species/year ○ First life on Earth? Archaebacteria ■ ARCHAE: Very old, ancient ■ Many are extremophiles ● EXTREMO: Extreme ● PHIL: to love 6) What is Global Warming, and is it "real"? What are the possible causes? What is a greenhouse gas? The increase of which greenhouse is most important in producing Global Warming? How are humans contributing to this increase? ● Global Warming: Our Earth heating up. YES, it’s real! ● Causes? Greenhouse Effect ● Greenhouse Effect: Solar energy comes in and some reflects back into space while some of it gets stuck and is prevented from getting the earth causing it to warm the earth. (heat gets trapped, without it we’d be too cold) ● Main Greenhouse Gases: Carbon Dioxide, Chlorofluorocarbons, Nitrous Oxide, Sulfur hexafluoride, Methane ○ By Human activities: Burning fossil fuels, agriculture, deforestation, industrial processes ● ↑CO2 → ↑ Acid 7) List and provide a brief description of the three domains and six kingdoms that are used to classify organisms, and provide examples of organisms within each of the kingdoms.

Prokary / Eukary

Unicell / Multicell

Domain

Kingdom

Archaebacteria (old)

Prokary

Archae

Bacteria

Eubacteria

Prokary

Mode of Nutrients (Producers, Consumers, Decomposers)

Examples

Unicell.

All (P, D, & C)

Some are extremophiles (boiling temps = thermophiles, high salt = halophiles, extreme pH’s, love for sulfur

Unicell.

All (P, D, & C)

Escherichia (Ecoli), Salmonella, Staph

(true)

Eukary

Protists

Eukary

Mostly Uni / Some Multi

All (P, D, & C)

Unicellular: Paramecium, Ameoba, Algea Multicellular: Seaweed, kelp

Fungi

Eukary

Mostly Uni / Some Multi

Decomposers

Mold, yeast

Plants

Eukary

Multicell.

Producers

Plants

Animals

Eukary

Multicell.

Consumers

Animals and Humans

*All bacteria is prokaryotic and everything else is Eukaryotic Modes of Nutrition: Autotrophs vs Heterotrophs Self T o Feed Diff/Other To Feed Producers Consumers and Decomposers 8) Define the term, evolution, and describe how evolution of a population is thought to occur through natural selection (in a very basic manner – the light moth/dark moth example discussed in class is a good place to start). ● Evolution: to change or diversify over long periods of time/ change in the allele frequency of specific genes ■ Alleles: different versions of specific genes ○ Inherited changes that build on each other ● In order for evolution to occur, you need: ○ 1. Genetic variety must be present ○ 2. Driving “force” to change the frequency of alleles ■ Ex: Further mutations, migration, natural selection, etc. ● Peppered Moth: ○ Prior to the industrial revolution, the light ones thrived. After, the dark ones thrived because they were more “fit” since they blended in better with the ashes/ pollution that were on all the trees from the revolution. ● Fitness: Ability to make babies and leave your genes 9) List, step-by-step, how a biologist initiates and proceeds through a scientific investigation. Briefly describe each of these steps. ● Scientific Method: process scientists follow to when trying to answer a question ● 1) Make an observation: Notice something ● 2) Ask a question: Wonder why its happening ● 3) Form a hypothesis: Educated guess ● 4) Design an experiment: tests the hypothesis ● 5) Collect and analyze data: finds evidence to prove hypothesis right or wrong ● 6) Make a conclusion: proves h ● ● ypothesis right or wrong based on evidence

10) What is a scientific hypothesis, and how does a hypothesis become a theory? What is a theory? ● Scientific Hypothesis: is an educated guess about a certain topic. A scientific hypothesis becomes a theory when enough evidence is found through experimentation and observation to support it. ● Theory: a prediction that is backed up with reasoning and research. It is almost set in stone with lots of evidence to back it up. ● Law: something that cannot be refuted/broken by the universe.

Lecture Topic 2 1) Define the following: element, atom, proton, electron, neutron, atomic number, mass number, isotope, ion. ● Element: Make up everything (on the periodic table) ● Atom: Make up elements. Always electrically neutral. Made up of subatomic particles. Defined by # of protons it contains. ● Protons, Electrons, Neutrons: ↓ Subatomic Particle

Electrical Charge

Relative Size

Location within atom

Protons

+1

Big (same as Neutrons)

Center (Nucleus)

Electrons

-1

Tiny

Outer Rings

Neutrons

0

Big (same as Protons)

Center (Nucleus)

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Atomic Number: # of protons an atom contains Mass Number: # of protons + # of neutrons Isotope: Isotopes of an element always have the same atomic #, but can have varying #s of neutrons ○ Radioactive Isotopes: Unstable forms of isotopes because they have too many neutrons and therefore, too much energy → release energy by omitting radioactive decay ■ ↑ Energy = ↓ Stability = ☹ ■ ↓ Energy = ↑ Stability = ☺ ■ Why is this so dangerous?? ● 1) Under very severe radiation → whole cell death ● 2) Denature Proteins ● 3) Mutates DNA → Could cause cancer ■ Good uses of Radioactivity? ● 1) Nuclear power ● 2) Irradiation of food ● 3) PET scan → diagnose cancer/ alzheimer's ● 4) Thyroid Scan ● 5) Radiation Therapy Ion: an atom or molecule with a net electric charge due to the loss or gain of one or more electrons.

2) Discuss different ways that investigators can use radioactive isotopes in scientific and medical studies. ● Nuclear power: when contained, it is considered clean ● Emits energy to kill bacteria off of food ● Diagnostic tests: PET scan (cancer/ alzheimer's) ● Thyroid scan: radioactive iodine

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Radiation Therapy: very specific, however could mutate surrounding cells

3) Describe the “shell” system of electrons orbiting around the nucleus in a particular element. How many electrons are allowed in the 1st, 2nd, and 3rd shell? ● Shell(s) of an element contain its electrons. ○ 1st shell (closest to the nucleus): contains up to 2 electrons ○ 2nd shell: can hold a max of 8 electrons ○ 3rd shell: can hold a max of 8 electrons *If outer shell is full, there can be no chemical bonding 4) Describe the types of chemical bonds that are important in life, including ionic bonds, non-polar and polar covalent bonds, and hydrogen bonds. ● Chemical bonds fill the outer shell of an atom ○ Ionic bond: steals or gives away electrons; very strong in solid form/ weak in water ○ Covalent bond: when two atoms share a pair of electrons (either a single or double bond)/ they donate one or two of their own electrons to form one or two shared pairs ■ Polar: unequal sharing of electron pair(s) in bonded atoms Exists between 2 identical atoms Hydrophilic (loves water) ■ Non-polar: equal sharing of electron pair(s) in bonded atoms Exists between any non-polar atoms - two different atoms Hydrophobic (hates water) ○ Hydrogen bond: A weak bond between a slightly positive charged hydrogen and a slightly negative charged second atom (usually oxygen or nitrogen)/ already shares a covalent bond 5) Discuss the important properties of water, including its ability to act as an ideal solvent for polar molecules, its temperature-stabilizing effect, and its cohesiveness. 1. Water absorbs heat with little temperature change a. Heat has to break apart water molecule bonds before water will boil (molecules will move) 2. Water has a rather high heat of vaporization a. To become a gas, all water molecules need to break all their bonds at the same time i. Sweating doesn’t cool down, evaporation does ii. When humidity is high, sweat can’t evaporate 3. Ice floats a. The colder the temperature, the closer water molecules move together until temperature reaches the freezing point. b. Freezing temperature (0 degrees Celsius) causes water molecules to move farther apart. The density lowers and the molecules become more stable. c. Frozen water has a lower density than liquid water which allows it to float 4. Water has a high surface tension a. Water forms many hydrogen bonds b. It takes more energy to break these bonds because of water's attraction to itself (cohesion) and other polar molecules (adhesion) through hydrogen bonds 6) Discuss the principles of the pH scale, and the difference between an acid and a base.

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Acid: A substance that releases (or donates) free H+ when dissolved in a solution Base: A substance that combines with (accepts ) free H+ from a solution Each unit change in pH represents a 10-fold change (10 x 10) in H+ levels ↑ H+  = ↑ Acidity (H+ = Acid)

7) Discuss the difference between a solution of pH 3 and a solution of pH 5 with respect to H+ content. Be able to do this with any two pHs. ● pH3 and pH5 are both acids but the  difference in hydrogen ion concentration between solutions of pH 3 and pH 5 is 100-fold, and the pH 3 solution has a higher hydrogen ion concentration than pH5 8) What is a buffer? How does it work? What important buffer is used to maintain the pH of our blood? Discuss the chemical equation that describes this buffering action and how it works in our bodies. ● Buffer: A substance that resists changes in pH ● They react with any added acids or bases ● Bicarbonate: The buffer we use to maintain the pH in our blood ● H+ + HCO3 - ↔ H2CO3 ↔ H2O  + CO2 ○ (Acid) + (Bicarbonate [baking soda]) ↔ (Carbonic Acid) ↔ (Water) + (Carbon Dioxide) ● H+ = CO2 in terms of effect on pH ● ↑ CO2 = ↑ H+ = ↓ pH 9) Provide a definition for the term, organic compound, and discuss why carbon is such an important component of biological macromolecules. How many covalent bonds can carbon form with other atoms? Organic compound: molecules containing carbon - a chemical compound that includes a carbon atom that is linked to atoms of other elements ● ●

Carbon is an extremely important biological component because it can form the basis of so many different types of molecules. Carbon can form 4 covalent bonds with other atoms

10) Describe and discuss the properties of the four major types of organic molecules/macromolecules found in living organisms: carbohydrates, proteins, nucleic acids, and lipids. Provide examples of each molecule we listed in class (there are several for each type), and describe/discuss their characteristics. What are the monomers that make up these macromolecules? How is a polymer formed from monomers? How are monomers released from polymers? Is dehydration synthesis an anabolic or catabolic reaction? What about hydrolysis? ● Carbohydrates ○ Most important carbohydrate is glucose (C6 H12  O6 ) ■ Often appears simplified in a “ring” form ○ All carbohydrates are made up of monomers (monosaccharides) ○ Basic abbreviation for one carbohydrate: (CH2O)n ■ n=3-7 ○ There are many different versions of carbohydrates because of carbon’s versatility to form different bonds ○ Oxygen and Nitrogen in molecules are extremely polar (dissolve in water)

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Functions of monosaccharides ■ Immediate energy: ● Directly absorbed from mouth into bloodstream ● Is the preferred source of energy ■ Carbon skeleton of monosaccharides can be used to generate other important molecules needed for other functions ■ Structure ● Plants use carbohydrates (cellulose) for structure (cell wall) ○ Disaccharides ■ Maltose ● Glucose + glucose ● Found in grains, when soaked in water fermentation occurs and forms beer sugar (maltose) ● When ingested, our body separates maltose using hydrolysis to separate into two glucose molecules ■ Lactose ● Glucose + galactose ● Found in dairy products ● Enzyme called lactase breaks down lactose ● Natural selection (famine) selected a majority of people who could produce lactase ■ Sucrose ● Glucose + fructose ● Table sugar ○ Polymers (Polysaccharides) ■ Many monomers linked together (polyglucose) ■ Functions: ● Long term storage unit of energy ● Stores energy in a polymer of glucose ● Cells can break down glucose at will when needed ■ Animals store excess glucose in polymer form as glycogen ● Humans store glycogen in liver ● Muscles also store glycogen, except only for themselves ■ Plants store excess glucose in polymer form as starch ● Potatoes are mostly starch ■ Chitin is a polyglucose with variation ● Found in exoskeleton of arthropods (ie. lobster, spiders, etc) Proteins (polypeptides- many proteins) ○ Functions: ■ Structure ● Silk protein in spiderwebs and collagen in skin ■ Transport ■ Most enzymes are proteins (catalyse reactions) ○ Hydrocarbon: molecule made of entirely hydrogens and carbons (extremely non-polar, hydrophobic) ○ Make proteins by linking amino acids using dehydration synthesis (anabolic  process) to remove peptide bond ○ The folding of a protein gives it its function

Globular: looks like a blob ● Ie. Protein channels and gates ● Most common ■ Fibrous: looks like strings or wires ● Ie. collagen, spiderwebs Primary structure: linear amino acid sequence ■ Represents sequence of amino acids and peptide bonds (strong) ■ Genes (DNA) codes for each of proteins ■ Oxygen atoms have high electronegativity ■

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general structure of an amino acid

Every 4 peptide bonds, there is a hydrogen bond Sickle cell anemia occurs when protein isn’t folded properly, so it denatures, removing it’s function of carrying oxygen Nucleic Acids ○ Polymers of DNA and RNA

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Deoxyribose has one less Oxygen molecule on the 2nd Carbon ■ Deoxyribose meaning to remove an oxygen RNA is single stranded vs. DNA which is double stranded DNA Polymerase replicates DNA (heat DNA Polymerase and DNA to multiply DNA) RNA pairs up with DNA to copy information to exit nuclear pore to cytoplasm where ribosomes  translate mRNA (RNA+DNA strands) into proteins DNA⟶transcription⟶mRNA⟶translation⟶proteins Sugars and phosphate link up (dehydration synthesis) to form long chain of nucleotides

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DNA ■ C-G, A  -T RNA ■ C-G, A  -U We have 23 chromosomes (lots of DNA wrapped together) from Mom and 23 from Dad=46 DNA replicates semi-conservatively, which means half is from each parent Ribose: 5 carbon ...