Week August 6 to August 10: Scientific Method and Organelles

Book: Biology for a Changing World
           Michele Shuster, Janet Vigna, Gunjan Sinha, Matthew Tontonoz

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Chapter 1: Process of science:

Scientific method includes:

• Making an observation
  
• Asking a question
  
• Forming a hypothesis
  
• Conducting an experiment,
  
• ​Getting results that can be measured
  
• Accept or reject hypothesis 

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Write down the definitions found in your book:

​Hypothesis: the starting point of your investigation, a proposed explanation based on limited evidence

Question: what you are exploring, it is not in the book, but it literally means question 

Experiment: a way to explore your question and test your hypothesis

Experimental group: the people or beings of subjects that you are studying, the group that
experiences the experimental intervention

Control group: a group that does not experience the experimental intervention

Placebo: fake treatment

Placebo effect: effect that we see when members of a control group display a measurable response to a placebo

Independent variable: factor being deliberately changed in the experiment

Dependent variable: measured result of an experiment, seen in both the experimental group and the control group

Sample size: number or subjects in the experiment

Result: measurable by units, what you learned

Evidence based conclusion: your result and seeing how it relates to your hypothesis

Scientific theory: a hypothesis that is supported by many years of rigorous testing and thousands of experiments
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Chapter 2: elements of Life

Five functional traits of life, pg 23:

Growth: And increase in the organism's size as the number of cell making up the organism increases.

Reproduction: the process of producing new organisms, offspring are similar but not necessarily identical to their parents in general structure, function, and properties.

Homeostasis: organisms maintain a stable internal environment, even when the external environment changes.

Sense and respond to stimuli: organisms respond to stimuli in many ways, they may move toward a food source r away from a threatening predator.

Obtain and use energy: all living beings require an input of energy to power their activities.  organisms obtain energy from food (which they either produce themselves or consume from the environment).  Chemical reactions convert that energy into usable forms.  The sum total of all these reactions is metabolism.

Review of chemistry, important terms:

• Element: a substance whose atoms all have the same number of protons, same atomic number
• Matter: anything with mass, physical substance
• Atom: basic unit of a chemical element
• Proton: subatomic particle with positive electric charge, equal in size to an electron but of opposite charge
• Electron: subatomic particle with a charge of negative electricity, found in all atoms, primary carrier of electricity
• Neutron: subatomic particle of about the same mass as a proton but without an electric charge, present in all except those of ordinary hydrogen
• Monomer: a molecule that can be bonded to other identical molecules to form a polymer
• Polymer: a substance that has a molecular structure consisting chiefly or entirely of a large number of similar units bonded together
• Nucleus: positively charged central core of an atom, has protons and neutrons 
• Organic molecule: composed of carbon atoms in rings or long chains to which are attached other atoms such as hydrogen, oxygen, and nitrogen
• Inorganic molecule: composed of other elements, not a combination of hydrogen and carbon
• Carbohydrate: large group of organic compounds, include sugar, starch, and cellulose
• Monosaccharide: any of the class of sugars that cannot by hydrolyzed to give a simpler sugar 
• Protein: built from building blocks called amino acids
• Lipid: organic compounds that are fatty acids or their derivatives and are insoluble in water but soluble in organic solvents, oils and waxes
• Nucleotide: a compound consisting of a nucleoside linked to a phosphate group, nucleotides form the basic structural unit of nucleic acids such as DNA
• Nucleic acids: a complex organic substance present in living cells, expecially DNA or RNA, whose molecules consist of many nucleotides linked in a long chain
• Macromolecules: a molecule containing a very large number of atoms, such as a protein, or synthetic polymer

Activity: work in groups of three or four, split up the words in the list into groups of four and look for the definitions in the book. Then share the definitions with each other:

Types of bonds:
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• Ionic bond: the complete transfer of valence electron(s) between atoms. It is a type of chemical bond that generates two oppositely charged ions. In ionic bonds, the metal loses electrons to become a positively charged cation, whereas the nonmetal accepts those electrons to become a negatively charged anion. Ionic bonds require an electron donor, often a metal, and an electron acceptor, a nonmetal. 
• Covalent bond: the sharing of electrons between atoms. This type of bonding occurs between two atoms of the same element or of elements close to each other in the periodic table. This bonding occurs primarily between nonmetals; however, it can also be observed between nonmetals and metals.
• 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.​

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Components:
  

• Phospholipids: a lipid with a phosphate group in its molecule
• Hydrophobic: does not like water
• Hydrophilic: likes water

Dissolving:

• Solvent: able to dissolve other substances
• Solute: component in a solution, what is dissolved in the solvent
• Solution: a mixture, with a solute in a solvent

​Water terms:
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• Polar molecule: must contain polar bonds due to a difference in electronegativity between the bonded atoms
• pH:  is a measure of hydrogen ion concentration; a measure of the acidity or alkalinity of a solution
• Acid: Solutions with a pH less than 7 are acidic
• Base: pH greater than 7 are basic
• Hydrogen bonds in water: Polar molecules, such as water molecules, have a weak, partial negative charge at one region of the molecule (the oxygen atom in water) and a partial positive charge elsewhere (the hydrogen atoms in water).
• Adhesion: is the tendency of dissimilar particles or surfaces to cling to one another
• Cohesion: cohesion refers to the tendency of similar or identical particles/surfaces to cling to one another, water is attracted to water

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Chapter 3: cells and how they work

COvered 8/9/2018, 8/10/2018

Types of cells:

• Prokaryotic cells
• Eukaryotic cells

​Prokaryotic cells have a cell wall, eukaryotic cells do not

What is in the cell? Organelles

• Cell membrane
• Cytoplasm
• Ribosome
• Nucleus
• Nuclear envelope
• Mitochondria
• Endoplasmic reticulum
• Golgi apparatus
• Lysosome
• Cytoskeleton-microfilament, intermediate filaments, microtubules
• Chloroplasts are in plants

Ways of cell communication:

• Osmosis
  
• Simple diffusion
  
• Transport proteins
  
• Facilitated diffusion
  
• Active transport
  

Endosymbiosis: the theory that free-living prokaryotic cells engulfed (ate) other free-living prokaryotic cells billions of years ago, forming eukaryotic organelles such as mitochondria and chloroplasts
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Bacteria

• Peptidoglycan
• Gram-positive
  
• Gram negative
  
• Simple diffusion