The Scientific Study of Life
Define homeostasis:
The process by which an organism maintains a stable internal environment despite changes in the external environment. Homeostasis is kept in check with negative feedback loops.
What is the difference between atoms and molecules?
Atom is the smallest piece of an element that retains the characteristics of the element.
Molecule is two or more atoms bonded together
What are the components of cell theory?
1. All organisms are made of one or more cells
2. The cell is the fundamental unit of life
3. All cells come from preexisting cells
Can you prove anything in science?
NO!! Science can be supported or not, it can also be disproved, but nothing can ever be proven.
What causes polar bonds?
Uneven distribution of charge/ Differences in electronegativity
What are the steps of the Scientific Process? (Six Steps)
1. Make Observation
2. Ask Question
3. Form Hypothesis
4. Make Prediction
5. Collect and interpret data
6. Draw conclusions
Describe a likely way two water molecules will interact with one another. (Think bonds)
A hydrogen bond will form between the hydrogen atom of one water molecule and the oxygen atom of the other water molecule.
What are characteristics of all cells?
1. Ribosomes
2. Cytoplasm
3. Cell Membrane
4. Genetic Material
What are the primary elements in all living organisms?
Sulfur
Phosphorus
Oxygen
Nitrogen
Carbon
Hydrogen
What are limits in science?
Ethics, Morality, Politics, Believing vs Knowing
Define life and how is it organized?
Life is the quality that separates living things from non-living matter.
Atoms ->Molecules -> Cells -> Tissues ->Organs ->Organ Systems -> Organisms -> Population of species -> Ecosystem with different species -> Biosphere
List at least three functions/properties that water has:
- Participates in chemical reactions (Hydrolysis and Dehydration Synthesis)
- Cohesion and adhesion
- Surface Tension
- Evaporative Cooling
- Provides force or support
- Removes toxic waste components
- Lubrication
Describe a cell membrane
Lipid bilayer (hydrophobic tail, hydrophilic head), components can move around (fluid mosaic), also contains sugars, cholesterols, and proteins
What is the structure of an atom?
Nucleus made of protons (positive charge) and neurons (neutral charge). Electrons (negative charge) exist in a cloud outside of the nucleus. Protons and neutrons are large, electrons are smaller.
Define: Exocytosis and Endocytosis
Exocytosis: uses vesicles to transport substances out of cells.
Endocytosis: allows a cell to engulf fluids and large molecules and bring them into the cell.
Define:
Observation
Hypothesis
Theory
Law
Observation: Gathering information about living things or nature using your senses or scientific tools
Hypothesis: A proposed, testable explanation for an observed phenomenon or biological question. If then statement.
Theory: A well-tested and widely accepted explanation for how or why something in the natural world works
Law: Describes a consistent pattern or rule about how living things work
What are the different kinds of chemical bonds, give an example of each:
Covalent Bonds- Share electrons, can be polar or non polar (H2)
Ionic Bonds- Transfer electrons (salts, NaCl)
Hydrogen Bonds- positive and negative charges attract (Holds DNA together)
Explain the processes of:
Simple Diffusion
Facilitated Diffusion
Osmosis
Active Transport
Simple Diffusion: Movement of particles from an area of high concentration to an area of low concentration without energy or helper proteins (passive)
Facilitated Diffusion: the passive movement of molecules across a cell membrane from an area of high concentration to an area of low concentration with the help of transport proteins (passive)
Osmosis: the passive movement of water molecules across a selectively permeable membrane from an area of low solute concentration (high water concentration) to an area of high solute concentration (low water concentration)
Active Transport: a cell uses energy to move molecules across its membrane against a concentration gradient, going from a low concentration to a high concentration
Define emergent properties. Give examples:
Characteristics of a system that cannot be predicted or explained solely by examining its individual components
Examples:
What are the three domains of life, are they prokaryotes or eukaryotes, what makes them unique?
1. Bacteria (prokaryote) -> single celled, no nucleus, circular chromosomes, peptidoglycan cell wall
2. Archaea (prokaryote) -> single celled, extreme environments, non peptidoglycan cell wall
3. Eukarya (eukaryote) -> single or multi celled, membrane bound organelles, not all cells have cell walls
Create a graph based on this scenario: I want to test if the use of fertilization makes a plant grow taller. Plant A is not given any fertilizer, Plant B is given fertilizer, each plant was placed on the windowsill and got 2 inches of water a day. After the experiment is run it is determined that the plant with fertilizer on average grew three inches taller than the other plant. Create and label graph!
Show me your graph.
Compare and Contrast the four Macromolecules:
1. Proteins
Monomer: Amino Acids. Variable R groups. Protein folding can occur up the the quaternary structure.
2. Carbohydrates
Monomer: Monosaccharides. Chains are called polysaccharides. ex. Glucose, Cellulose, Starch. Short term energy.
3. Lipids
Monomer: N/A. Made of a glycerol backbone and fatty acid chains. Energy-rich, can be saturated, unsaturated, or trans.
4. Nucleic Acids
Monomer: Nucleotides. DNA has ATGC, RNA has AUGC. DNA is double stranded, RNA is single stranded.
What is/ how does the sodium potassium pump work and what kind of transport is it?
The sodium potassium pump is a form of active transport, largely found in never cells (neurons) to aid in generating action potentials. It works by taking three sodium out of the cell and transporting two potassium into the cell.
Draw and label an action potential
Show me
Define Dehydration Synthesis and Hydrolysis:
Dehydration Synthesis: An enzyme binds two monomers together, releasing a water molecule
Hydrolysis: Reverse reaction of dehydration synthesis; breaks polymers into monomers and requires a water to do so.