Mrs. Jackson’s Absolute Bare Minimum Module 1 Review

1. Mrs. Jackson’s Absolute Bare Minimum Module 1 Review

2. An organism is any individual living thing. • Living things share some common characteristics: • All need energy for metabolism. • Metabolism: All of the chemical processes in an organism that build up or break down materials. • All are made of one or more cells. • All respond to their environment. • Stimuli, or physical factors, include light, temperature, and touch. • All have genetic material (DNA) that they pass on to offspring (universal code)

3. _ O H H + + Life depends on hydrogen bonds in water. • Water is a polar molecule. • Polar molecules have slightly charged regions. Atom: Oxygen Charge: Slightly negative • Hydrogen bonds • form between slightly positive hydrogen atoms and slightly negative atoms. (oxygen) Atom: Hydrogen Charge: Slightly positive • Nonpolar molecules do not have charged regions.

4. High Specific Heat: water resists changes in temp. • Provides stability of temperature for land masses surrounded by water & for the temperature of the human body, & makes it an effective cooling agent. • Cohesion: water molecules stick to each other. • Adhesion: water molecules stick to other things. • Ice floats on water: one of the only solids to float on its liquid form – due to arrangement of water molecules due to charged regions. Provides insulation for water below (stays at about 4 degrees C – freezing point is 0 C) • Hydrogen bonds are responsible for important properties of water.

5. solution Many compounds dissolve in water. • A solution is formed when one substance dissolves in another. A solution is a homogeneous mixture. • Solvents dissolve other substances. • Solutes dissolve in a solvent.

6. Polar solvents dissolve polar solutes. • Nonpolar solvents dissolve nonpolar solutes. • Polar substances and nonpolar substances generally remain separate. • Example: Oil (non-polar) and water (polar) • “Like dissolves like.”

7. pH <7=Acid (more H+) 7=Neutral >7=Base (less H+) Maintaining homeostasis *Buffer: Helps to maintain pH.

8. Speaking of homeostasis… • Homeostasis refers to your body maintaining stable, constant internal conditions. • This may include: • Regulation of temperature (thermoregulation) Ex.: sweating during exercise • Regulation of pH (i.e. buffers) • Regulation of oxygen delivery (for cellular respiration!). Ex: heart beating faster during exercise • Regulation of water (osmoregulation - regulation of water concentrations in the bloodstream, effectively controlling the amount of water available for cells to absorb.)

9. Control systems work together through feedback • Feedback: Information from sensor that allows a control center to compare current conditions to a set of ideal values. • Feedback loop: Sensorcontrolcentertargetsensor…. • Negative feedback loops: control system counteracts any change in the body that moves conditions above or below a set point (reversing change to return conditions to their set points)-most functions in the body are regulated this way. • Ex.: Thermostats, holding your breath • Positive feedback loops: Control center uses information to increase rate of change away from set points. • Ex.: Cut finger increases clotting factors in blood.

10. Carbon atoms have unique bonding properties. 1. Carbon forms covalent bonds (strong bonds) with up to four other atoms, including other carbon atoms (has 4 unpaired electrons in its outer energy level) 2. They can form large, complex molecules

11. Carbon atoms have unique bonding properties – Slide 2 3. Carbon can form single, double, or triple bonds 4. Carbon forms isomers • Isomers are compounds that have the same chemical formula, but different structural formulas • Example: C4H10 • Only carbon has these 4 characteristics

12. Many carbon-based molecules are made of many small subunits bonded together. • Monomers are the individual subunits. • Polymers are made of many monomers.

13. Carbohydrates

14. Lipids LIPIDS

15. Proteins

16. Nucleic acids

17. How are polymers made from monomers? • This is dehydration synthesis. During this type of reaction, a water molecule is removed (an –OH from one simple monomer and an –H from another to form a water molecule. This joins two monomers together to form a polymer. When adding another monomer to the dimer, another water molecule needs to be removed. Monomer called Glucose monomer-OH + monomer-H polymer + H2O Dimer called Maltose

18. Hydrolysis • A polymer needs to break apart (the carbs, proteins, and lipids we ingest are too big for us to use) • Water breaks apart into (-OH) and (-H) and splits the polymer into monomers • The (-OH) and (-H) bond to each monomer to make them stable molecules • polymer+ H2O  monomer-OH + monomer-H

19. Chemical reactions release or absorb energy. • Catalysts are substances that speed up chemical reactions • Decrease activation energy • Increase reaction rate Activation energy is the amount of energy that needs to be absorbed to start a chemical reaction

20. Enzymes allow chemical reactions to occur under tightly controlled conditions. • Enzymes are catalysts in living things. • Enzymes are needed for almost all processes. • Most enzymes are proteins.

21. Disruptions in homeostasis can prevent enzymes from functioning. • Enzymes function best in a small range of conditions. • Changes in temperature or pH can break hydrogen bonds – DENATURES enzyme (changes 3D structure) • An enzyme’s function depends on its structure.

22. An enzyme’s structure allows only certain reactants to bind to the enzyme. Substrates: reactants that bind to an enzyme Active site: area on the enzyme where substrates bind

23. What else can affect enzyme activity? • Enzyme Concentration If we keep the concentration of the substrate constant and increase the concentration of the enzyme, the rate of reaction increases linearly. (That is if the concentration of enzyme is doubled, the rate doubles.) This is because in practically all enzyme reactions the molar concentration of the enzyme is almost always lower than that of the substrate. • Substrate Concentration If we keep the concentration of the enzyme constant and increase the concentration of the substrate, initially, the rate increases with substrate concentration, but at a certain concentration, the rate levels out and remains constant So at some point, increasing the substrate concentration does not increase the rate of reaction, because the excess substrate cannot find any active sites to attach to.

24. Exothermic reactions release more energy than they absorb. • Excess energy is released by the reaction. • Energy “exits” the reaction. (Exo = exit)

25. Endothermic reactions absorb more energy than they release. • Energy is absorbed by the reaction to make up the difference. • Energy goes into the reaction. (Endo = “into”)

26. The Cell Theory: • All organisms are made of cells. • All cells come from other cells. • The cell is the basic unit of structure & function in living things.

27. All cells share certain characteristics. • Cells tend to be microscopic. • All cells are enclosed by a membrane. • All cells are filled with cytoplasm. • All cells have ribosomes. • All cells have genetic material (DNA)

28. There are two cell types: • Eukaryotic cells • Have a nucleus • Have membrane-bound organelles • Prokaryotic cells • Do not have a nucleus (still have DNA) • Do not have membrane-bound organelles

29. Review Eukaryotes Prokaryotes No nucleus (still have DNA) No membrane-bound organelles Smaller size because of lack of organelles Less complex Unicellular • Have nucleus (DNA) • Have membrane-bound organelles • Larger size because of organelles (Organelles divide up the functions of the cell and allow eukaryotic cells to have more volume.) • More complex • Unicellular or multicellular

30. Organelles and Functions See 3.1/3.2 PowerPoint! How do membrane-bound organelles facilitate the transport of materials within the cell? The rough ER works with the Golgi… • Vesicle: Small membrane-bound sacs that divide some materials from the rest of the cytoplasm and transport these materials within the cell. • Proteins (such as secretory & membrane proteins) made by ribosomes on the rough ER are packaged in vesicles and sent to the cell membrane or Golgi Apparatus. • The Golgi Body processes & sorts the proteins, then packages them into vesicles for storage, transport, or secretion from the cell membrane in new vesicles.

31. Levels of Organization • OrganellesCellsTissuesOrgans  Organ SystemsOrganisms

32. There are advantages to being multicellular rather than unicellular. These include allowing: • Allows the organism to be larger & have more efficient movement • Cell differentiation (having different types of cells with different functions) – specialization of cells, tissues, organs, organ systems allows for efficient performance of a variety of functions. • The organisms to be more complex

33. Cell membranes are composed of two phospholipid layers. • The cell membrane has two major functions • Forms a boundary between inside and outside of the cell • Controls passage of materials in & out of cell

34. Phospholipid Bilayer • Forms a double layer surrounding a cell • Head is polar (attracted to water) and forms hydrogen bonds with water • Tails are nonpolar (repelled by water)

35. Passive transport does not require energy (ATP) input from a cell. • Molecules can move across the cell membrane through passive transport. • Three types of passive transport: • Diffusion: movement of molecules from high to low concentration • Osmosis: diffusion of water • Facilitated diffusion (see slide)

36. Diffusion and osmosis are types of passive transport (NO ENERGY) • Molecules diffuse down a concentration gradient. • High to low concentration

37. How do different solutions affect cells? • There are 3 types of solutions: • Isotonic: solution has the same concentration of solutes as the cell. • Water moves in and out evenly • Cell size stays constant

38. How do different solutions affect cells? • There are 3 types of solutions: • Hypertonic: solution has more solutes than a cell • More water exits the cell than enters • Cell shrivels or dies

39. How do different solutions affect cells? • There are 3 types of solutions: • Hypotonic: solution has fewer solutes than a cell • More water enters the cell than exits • Cell expands or bursts

40. Some molecules can only diffuse through transport proteins– this is FACILITATED DIFFUSION • Some molecules cannot easily diffuse across the membrane • Ex: glucose (needed by cell to make energy) • Facilitated diffusion is diffusion through transport proteins • DOES NOT USE ENERGY Video 

41. Active Transport • Cells use energy (ATP) to transport materials that cannot diffuse across a membrane. • Drives molecules across a membrane from lower to higher concentration • Goes against the concentration gradient

42. TYPES OF ACTIVE TRANSPORT • Endocytosis: Brings materials into cell (Endo=into) • Exocytosis: Releases materials out of cell (Exo=Exit) • Pumps (see next slide)

43. Sodium-Potassium Pump (A type of pump) • Uses a membrane protein to pump three Na+ (sodium ions) across the membrane in exchange for two K+ (potassium ions) • ATP (energy) is needed to make the protein change its shape so that Na+ and K+ can move through it and cross the membrane • Helps the heart contract, helps regulate blood pressure, allows neurons to respond to stimuli and send signals

44. Scientific Terms • Hypothesis: A proposed, testable answer to a scientific question. • Observation: the use of our senses, computers, and other tools to gather information about the world. • Ex.: Studying the interactions between gorillas by observing their behavior.

45. Other important science terms • Inference: A conclusion reached on the basis of evidence and reasoning. • Law:A law that generalizes a body of observations. At the time it is made, no exceptions have been found to a law. It explains things but does not describe them; serves as the basis of scientific principles. • Theory: A proposed explanation for observations and experimental results that is supported by a wide range of evidence – may eventually be accepted by the scientific community. • Principle: A concept based on scientific laws and axioms (rules assumed to be present, true, and valid) where general agreement is present. • Fact: An observation that has been repeatedly confirmed.

46. Controlled experiments • Only one independent variable should be changed in an experiment. • Other conditions must stay the same and are called constants. • Controlled experiments must have a control group – everything is the same as the experimental groups but the independent variable is not manipulated. • Example: When testing blood pressure medication, control group receives none of the active ingredient. • A large number of test subjects or trials is ideal.

47. Starch molecule Glucose molecule 4.1 How do living things get ATP? • ATP is the energy carrier in living things – it is usable energy for the cell. • ATP stands for Adenosine triphosphate. • Living things get ATP from breaking down carbon based molecules. (carbohydrates, lipids, proteins) • Needed for cellular activities (i.e. active transport)

48. phosphate removed This is how it works

49. Photosynthesis • The process of photosynthesis captures energy from sunlight and converts it into sugar (glucose). • This process happens in organisms called autotrophs or producers. (Need to make their own food) • This process takes place in an organelle called the chloroplast (this is a plastid). • The chloroplast has a green pigment in it called chlorophyll that is responsible for capturing the light energy.

50. So how does photosynthesis work? The first stage of photosynthesis is called the Light Dependent Stage. • Light is captured by the chlorophyll in the thylakoid of the chloroplast.