Biology Lab Midterm Review PDF

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Orientation: Metric System and Safety Terms ● International System of Measurement (SI) (metric system): used by scientists worldwide and is based on consistent, quantifiable measures; multiples of 10 ● Meter (m): unit of length in the metric system (centimeter (cm), millimeter (mm), kilometer (km) ● Gram (g): unit for mass (weight) (milligram (mg), microgram (μg), kilogram (kg) ● Liter (l): base unit for volume ● Calipers: an instrument used to measure length ● Meniscus: an upward or downward curve at the surface of liquid Know the difference in the units for length, mass, volume, and temperature ● Length: meter, millimeter, centimeter, kilometer ● Mass: gram, milligram, microgram, kilogram ● Volume: liter, milliliter, microliter ● Temperature: Celsius and Fahrenheit Be able to convert metric (SI) units- NOT given the conversion factors ● 19.7kg= 19,700g (x1,000) ● 3.9m=390cm (x100) ● 1.4kg= 1,400g ● 50,000mg= 50g ● 300kg= 300,000g Be able to measure length, mass, temperature, ad volume given a caliper, a balance, a micropipette, a thermometer (probeware sensor equipment) and a graduated cylinder

Lab 1: Scientific Method Terms ● Micropipettes: one of the primary tools of the laboratory biologist and it allows you to measure and dispense small and accurate volumes of liquid solutions; measures volumes as small as 2 μl and as large as 1000 μl (P20, P200, P1000) ● Inquiry: a method for the scientific method ● Experimental Design: refers to how the science is done and details the precise, data generating steps carried out within the laboratory ● Observations: to note and record something perceived by the senses ● Inferences: generalized developed from repeated observations ● Quantitative Data: able to be measured empirically and is represented by numerals ● Qualitative Data: represented by words and descriptions ● Independent Variable: a condition within the experiment that is manipulated by the experimenter; can be more than one ● Dependent Variable: a condition or component of the experiment that will change in response to manipulation of the independent variable; this change is what will be observed and/or measured during data collection ● Constant Variable: fixed aspects of the experiment that remain unchanged throughout the entire experiment

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Controls: devised to determine whether the results of the experiment would occur without the impact of the dependent variable; conditions that the experimenter actively sets and keeps the same throughout the experiment in order to isolate the effects of their manipulations of the independent variable ○ Negative Control: attempt to identify variables other than your independent variable manipulation that might give the same result (to rule out confounding factors) ○ Positive Control: factors that are known to produce a specific result (the result you are looking to see due to your manipulation of the independent variable) Hypothesis: a statement that postulates a relationship between the independent variables and the dependent variables, and acts as a basis for prediction of future experimental outcomes Repeated Measures: is important because you want to make sure that the experimental results are reliable and will occur in more than one instance; the more that you can repeat it, the better the experiment will be Reproducibility: results should be obtained by others who follow your very same experimental design; if you results cannot be reproduced, then they are due to some unforeseen variables

Be able to determine the independent and dependent variables using graph, table, or scenario ❖ Independent variables are always represented by the x-axis ❖ Dependent variables are always represented by the y-axis Be able to define the following words: interferences, observations, experimental design (qualitative and quantitative), independent variable, dependent variable, experimental group, control group, hypothesis, and replicates ● (Bolded terms at the top) Be able to tell the difference between a line graph and a bar graph AND be able to interpret the graph provided. What are the components of graphs? ● Line Graph: suited when the independent variable is continuous; when both variables are quantitative, the line segment that connects two points on the graph expresses a slope ● Bar Graph: common type of graph best suited for a qualitative independent variable; you cannot calculate a slope from the heights of the bars ○ Title: provides a brief description of the contents of the figure; it should include key elements ○ Name and Number: figures must be named and numbered in the order that they are referred to in your report ○ Y-axis Label: represents the dependent variable; must use the appropriate scale ○ X-axis Label: represents the independent variable; must use the appropriate scale ○ Body: the data is plotted as distance points or a set of bars Know the components of the experiment that you performed in the lab. For example, what was the procedure? What did you measure in the experiment? What was the instrument used in the experiment? What was the conclusion? ● Procedure:

Lab 2: Basic Chemistry of Cells Terms

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Element: anything that cannot be broken down into a sampler substance and still retain its unique chemical properties Atom: the smallest unit of matter that makes up an element; they can be broken down into subatomic particles (protons, neutrons, electrons) Molecules: atoms react with one another, forming chemical bonds to make them Chemical Formula: a form of shorthand used by scientists to write these molecules; indicates the identify and the number of each element in the molecule (H20 & NaCl) Biomolecules: molecules found in living systems that contain five or more carbon atoms in either ring or chain formation ○ Four Basic Types of Biomolecules ■ Carbohydrates ■ Lipids ■ Proteins ■ Nucleic Acids Monomers: simple molecules Polymers: complex molecules (two or more monomers linked together) Condensation Reaction: when two or more molecules can be linked together Hydrolysis Reaction: the reverse process of splitting a larger polymer into two smaller molecules by inserting a molecule of water Monosaccharides: basic building blocks for carbohydrates (one-sugar) (glucose & fructose) Disaccharides: two monosaccharides joined together (two-sugars) (table sugar & sucrose) Polysaccharides: monosaccharide molecules are linked together to form a medium-length chain (many-sugars) (starch, cellulose, glycogen) Triglyceride: the most common form of lipids; consists of a glycerol molecule combined with three fatty acids Amino Acids: basic unit of proteins Polymer: an amino acid that may fold into characteristic three dimensional shape that is essential to its function as an enzyme, carrier molecule, or other type of protein (DNA & RNA) Peptide Bond: bond between two amino acids Dipeptides & Polypeptides: short protein chains Nucleotide: the monomer of nucleic acids ○ Consists of Three Molecules ■ Five-carbon sugar ■ Nitrogenous base (adenine, thymine, guanine, cytosine) ■ One phosphate group Buffers: substances that stabilize pH by either releasing H+ if the solution is too basic or absorbing H+ if the solution is too acidic Buffering Capacity: a measure of its ability to resist change in pH; determined by adding small amounts of acid and base to the substance and checking the pH after each addition

Know the color change for investigation 1-3 using the different reagents and the different macronutrients. For example, Benedict’s Reagent tests for what substance and gives what color change? ● Investigation 1: Benedict’s Test ○ Benedict’s Reagent~ reducing sugars

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Positive~ green/orange/brown Negative~ blue

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Investigation 2: Sudan III Test ○ Sudan III~ Lipids ■ Positive~ bright/light orange ■ Negative~ no orange

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Investigation 3: Biuret Test ○ Biuret’s Reagent~ Protein ■ Positive~ purple ■ Negative~ blue

Know the simple procedure of how Investigation 1-3 was conducted. For example, what did you have to do to the simple sugars test to see the color change ● Investigation 1 Procedure: Obtain 6 test tubes and add the solutions distilled water, glucose, sucrose, starch, onion juice, and potato juice. The positive control is glucose and the negative control is distilled water. Heat the test tubes in warm bath water. And record the color change. ●

Investigation 2 Procedure: Obtain a piece of filter paper and use a pipette for the substances distilled water, cream, whole milk, milk, and salad oil to add to the paper. For three minutes let the paper soak in Sudan III solution. Rinse the paper with distilled water and record the results.

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Investigation 3 Procedure: Obtain 4 test tubes and add 20 drops of the solutions distilled water, egg albumin, starch, chicken broth. The positive control is albumin and the negative control is distilled water. Add 3 drops of Biuret reagent to each tube and gently shake. Record the results.

Know the macronutrients (macromolecule)- carbohydrates (starch and reduced sugars), lipids, proteins and nucleic acids- the lab demonstrated and what smaller molecules each of the macronutrients is converted into monosaccharides, fatty acid, and amino acid). Know the basics of pH scale. Which solutions in the experiment were acids? Bases? Neutral? ● The pH scale is a measure of the acidic or basic nature of a solution that ranges from 1 (very acidic) to 14 (very basic). Pure water has a neutral pH of 7. The scale is logarithmic, which means a solution within a pH of 5 is 10 times more acidic than a solution with a pH of 6. Know the two ways that we tested pH. Which way was more exact? ● pH paper ● pH meter (way more exact) Define buffers. How are they important in the body? ● Buffers: substances that stabilize pH by either releasing H+ if the solution is too basic or absorbing H+ if the solution is too acidic ● It’s important to the body because most cells can’t tolerate large changes in pH, so they use buffers to help maintain a relatively constant pH.

Lab 3: Cell structure and Microscopy Terms ● Cell: the smallest unit capable of sustaining life ● Cell Theory: the foundation of biology where cells themselves were not seen until the development of the microscope ● Plasma Membrane: the outer boundary of the cell ● DNA: genetic information that’s stored in all cells ● Cytoplasm: everything inside the plasma membrane that is not DNA or the nucleus ● Prokaryote: simpler cell with few internal compartments; DNA found in the cytoplasm and not the nucleus; no membrane- bound organelles (bacteria and archaea) ● Eukaryote: larger than prokaryotic cells and have a variety of internal compartments; contains membrane-bound organelles like mitochondria and chloroplasts; nucleus contains DNA (protists, plants, animals, and fungi) ● Compound Light Microscope: passes light through the specimen and then through two different lenses (parfocal~ once an object is in focus at low power, it will remain focus at the higher power ● Total Magnification: multiplying the magnification of the ocular lens by the magnification of the objective lens Be able to focus a microscope. ● Adjust the fine focus knob and light to make it focus and clear Know the proper care and handling of a microscope. ● When carrying the microscope you should hold it in a upright position with one hand on the base platform and the other on the arm of the microscope. Begin and end with the lowest power objective. make sure the light is turned to its minimum intensity before turning it on. Keep it clean and don’t remove any parts. Never use a paper towel or other materials besides grit free lens paper to clean the lens. Know the components and functions of a microscope. ● Base: the supportive flat surface of the microscope that rests on the table ● Substage Light: a light within the base providing the light source for illumination of the specimen; at the side or front of the base, turns it on or off, and a dial adjusts the light intensity ● Head (body tube): contains the rotating nosepiece and ocular lenses ● Ocular Lenses: the eyepieces that look through to observe the microscope specimen ● Nosepiece: the revolving device located below the ocular lenses; change from one objective lens to another ● Objective Lenses: attached to the nosepiece ○ Scanning (4x): shortest objective lenses ( red stripe) ○ Low Power (10x): used to view objects in greater detail ( yellow stripe) ○ High Power (40x): used to view in even greater detail ( blue stripe) ○ Oil Immersion (100x): view objects with the greatest magnification ( white stripe) ● Arm: connecting the head and base ● Stage: connected to the arm; includes mechanical stage or stage clips to keep the slide stationary during viewing

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Coarse Adjustment Knobs: largest knobs on the arm; raises and lower the stage, controls the focus, should only be used at scanning power (4x) or low power (10x) to avoid contacting the objective lens with the microscope slide Fine Adjustment Knobs: used for precision focusing Condenser: concentrates light on the specimen; raises and lowers it to control light intensity Iris Diaphragm Lever: opens and closes the iris diaphragm and regulates light passing through the condenser

Be able to calculate total magnification given the ocular and objective magnification. ● Ocular Magnification x Objective Magnification= Total Magnification ● Scan: 10X x 4X= 40X ● Low: 10X x 10X= 100X ● High: 10X x 40X= 400X ● Oil: 10X x 100X= 1000X Be able to explain and/or demonstrate how to put a slide in focus up to 40x objective. Remember you only need to use the fine focus as you go up in objective power! ● (Focus a Microscope) Know the structural differences between prokaryotes and eukaryotes. Be able to identify these features on a picture or microscope slide. ● Prokaryotes: single-celled organisms lacking well-defined nuclei and membrane-bound organelles and with chromosomes composed of a single closed DNA circle. It can come in the forms of minute spheres, cylinders and spiral threads, to flagellated rods, and filamentous chains. (bacteria) ● Eukaryotes: characterized by a membrane-bound nucleus and other specialized membranous organelles like the mitochondria, endoplasmic, reticulum, golgi bodies, lysosomes, etc. More complex than prokaryotes and larger in size. They contain a nucleus with DNA and chromosomes. Cell reproduction takes place by mitosis. Cytoplasm exhibits movement and ribosomes are present. They also have flagella which are projections that are long, slender motile cytoplasmic. (plant, animal, protists, fungi) Know the structural differences between plant cells and animal cells. Be able to identify these features (organelles) on a picture, model, or microscope slide. ● Both Plant and Animal Cells ○ Plasma Membrane: separates the cell from its external environment ○ Cytoplasm: internal substance of the cell; site of all chemical reactions ○ Nucleus: houses DNA ○ Nucleolus: ribosome subunit assembly ○ Nuclear Envelope: surrounds the nucleus ○ Nuclear Pore: for nuclear traffic ○ Chromatin: DNA and associated proteins, DNA contains genetic information ○ Rough Endoplasmic Reticulum: synthesizes proteins ○ Smooth Endoplasmic Reticulum: synthesizes lipids and steroids ○ Golgi Body: responsible for protein packaging and sorting ○ Mitochondria: responsible for ATP synthesis

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Plant Cells Only ○ Cell Wall: surrounds the cell for structural and mechanical support ○ Ribosomes: responsible for protein biosynthesis ○ Chloroplast: responsible for photosynthesis ○ Vacuole: responsible for storage of waste, nutrients, and water

Be able to identify the following organisms in a microscope and/or picture from a microscope ● Coccus Bacteria ○ Model

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Microscope

Bacillus Bacteria ○ Model

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Microscope

Spirillum Bacteria ○ Model

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Microscope

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Anabaena (a cyanobacteria): akinete, heterocysts ○ Model

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Microscope

Elodea (an aquatic plant): chloroplasts, cell wall, central vacuole, nucleus ○ Model

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Microscope

Onion Plant Cell (a general plant cell): cell wall, cytoplasm, nucleus, chloroplast ○ Model

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Microscope

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Cheek Animal Cell (a general animal cell): plasma membrane, cytoplasm, nucleus ○ Model

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Microscope

Be able to identify an unknown slide to determine if it is an animal, plant, or bacteria.

Lab 4: Osmosis and Diffusion Terms ● Hydrophilic: substances that easily dissolves in water (water-loving) ● Hydrophobic: substances that don’t dissolve in water (water fearing) ● Selectively Permeable: holds the plasma membrane together in aqueous environment and allows the

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membrane to perform one of its primary functions Transport Proteins: assist substances in moving across the membrane Diffusion: the simplest means by which substances cross the membrane; occurs when a solute moves from an high concentration to an area of low concentration; does not require any input of energy Osmosis: a special case of diffusion; movement of water, the solvent, dow its concentration gradient across a selectively permeable membrane Equilibrium: no further net movement from one side of the membrane to the other Tonicity: describes one solution’s solute concentration in comparison to another solution Isotonic: two solutions at equilibrium (the same solute concentration) Hypertonic: the solution with the higher solute concentration when two solutions are at different solute concentrations Hypotonic: the solution with the lower solute concentration

Know the following terms related to osmosis and diffusion in a cell: solvent, solute, selectively permeable, diffusion, osmosis, equilibrium, isotonic, hypertonic, hypotonic, plasmolysis, hemolysis ● (Bolded terms at the top) Know the GENERAL procedure and results from investigation 1-2 ● What does each procedure demonstrate within regards to diffusion or osmosis? ● For example, the dialysis tubing represents what organelle? ○ Cell membrane ● The dialysis tubing will allow the diffusion of what substances across its membrane? ○ Sucrose ○ Chloride Ion ● Know the reagents used in Investigation 2, what does each reagent test for? What is the precipitate? Which solutions or ions went across the dialysis tubing? Why? ○ Lugol’s Iodine~ Starch ■ Positive: blue-black ■ Negative: brown

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BaCl2 Solution~ Sulfate ions ■ Positive: white precipitate forms ■ Negative: no precipitate

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Silver Nitrate~ Chloride ions ■ Positive: milky-white precipitate forms ■ Negative: no precipitate

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Biuret Reagent~ Proteins ■ Positive: light lavender ■ Negative: bright blue

Know the difference between hypertonic, hypotonic, and isotonic solutions within a red blood cell and plant (onion) cell. Be able to identify in a picture and/or microscope slide.

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Onion Cell ○ Hypertonic (shrinks): 20% NaCl ○ Hypotonic (swells): distilled water Red Blood Cells ○ Hypertonic (shrinks): 10% NaCl ○ Isotonic (stays the same): 0.9% NaCl ○ Hypotonic (swells): distilled water

Lab 5: Enzymes Terms ● Metabolism: all the chemical reactions that occur in a cell are collectively ● Enzymes: biological catalysts that are made of proteins and function to increase the rate of chemical reactions to rates that are biologically useful ● Catalyze: accelerate reactions by lowering the activation energy needed by lowering the activation energy needed for the reaction to occur ● Substrate: a molecule that must bond with an enzyme ● Enzyme-Substrate Complex: when a substrate binds to an enzyme ● Transition State: the substrate becomes more reactive and the met...