Unit 2 Intro to Biology PDF

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Unit 2 Lesson objectives and notes...

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Unit 2: Basic Chemistry and Biological Macromolecules -Biological macromolecules- special molecules that contain carbon atoms covalently bonded with hydrogen atoms. -carbohydrates, lipids, proteins, nucleic acids Module 4: Atoms and Chemical Bonding -

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Describe what an atom is and the subatomic particles of which it is comprised - Atom is the foundational unit of matter - Made of even smaller subatomic particles called protons, neutrons, and electrons - Protons and neutrons reside in the nucleus  P= positive charge  N= Neutral charge  Each have a mass as 1 amu - Electrons  Negative charge  Almost no mass  Outside the nucleus in shells - When #P = #E = electronically neutral atom - Mass of atom = atomic mass - In biological systems, major elements are carbon, hydrogen, nitrogen, oxygen, phosphorus, and sulfur Identify different types of chemical bonds - Covalent- strong, between atoms in the same molecule, electron pairs shared, creating strong bond  Instead of transferring= share electrons - Ionic- moderately strong, between charged atoms, electron transfer  Trying to fill their outer shell  Cations - + charge  Anions - - charge - Hydrogen- weak, between atoms in different molecules or pairs of molecules, weak electrostatic attraction with opposite partial charges  Often develop a slight positive charge

Module 5: Water: A molecule Essential for Life -

Identify the special properties of water - Water is an excellent solvent and can dissolve a wide range of substances  Solvent: The component of the solution in the greatest quantity  Solutes: the component(s) present in lower quantities  Dissolves in the solvent - Water is cohesive  Water molecules are attracted to each other  Allows surface tension  Adhesion- water molecules bonding to other molecules - Water’s temperature tends to remain stable - Solid water (ice) is less dense than liquid water  Water molecules in ice are further apart than they are in liquid water due to the arrangement of the molecules in the solid

Module 6: Characteristics of Organic Molecules -

Describe the major characteristics of organic molecules

1. All organic molecules contain carbon atoms bonded to hydrogen a. Organic molecules also often contain oxygen, nitrogen, phosphorous, or sulfur 2. Atoms within organic molecules are connected by covalent bonds 3. Organic molecules are modular. Smaller organic molecules (monomers) can be linked together to make larger organic molecules (polymers). Larger organic molecules consist of a carbon skeleton (backbone) with other atoms branching off from this structure. a. Bonds between atoms in individual monomers can link the monomers together to form long strings of polymers i. Organic molecules are virtually limitless in their diversity. b. 4 major classes of biological macromolecules i. Carbohydrates- energy storage, cellular communication and structural support 1. Monomer- sugar ii. Proteins- essential for carrying out the necessary functions of life 1. Monomer- amino acids 2. Functions- structural components of tissues, facilitate and speed up biochemical reactions (enzymes); participate in communication iii. Nucleic acids- (such as DNA) essential for information storage within a cell and passing on this information to the next generation, 1. Monomers- nucleotides 2. Function- store genetic information, used in protein synthesis iv. Lipids- essential for energy storage and maintaining a boundary between the living organism and its environment 1. Monomer- fatty acids 2. Function- long term energy, structural components of membranes 4. Organic molecules are typically produced by living cells and are found in large quantities in living organisms and their remains. Humans have developed ways to synthesize organic chemicals artificially. Module 7: Carbohydrates -

Identify the basic structure and function of carbohydrates, lipids, and proteins - Carbohydrates- organic molecules that consist of carbon, hydrogen, and oxygen atoms in a 1:2:1 ratio.  Primary source of energy in living systems  Large complex carbohydrates can be used to store energy  Cellulose is a complex carbohydrate used in plants for structural support - Characteristics of Carbohydrates  Either simple or complex  Simple- made up of 1 or 2 sugar monomers o CH2O ratio o Monosaccharides (glucose, fructose)  Commonly C6H12O6  A common 5 carbon monosaccharide is ribose, which is the sugar component in RNA  DNA is ribose missing 1 O o disaccharides (lactose, maltose)  2 monosaccharides linked together by a covalent bond o Quickly and easily accessed to generate energy the cell can use

Complex- more than two sugar monomers covalently bonded together o Polysaccharides (Starch, cellulose)  Store energy for a larger period Function of Carbohydrates  Source of Stored Energy  Excess glucose are linked together to make a long branching polysaccharide called glycogen. o Stored in liver with small amount in the muscles o Once stores are filled, the body begins storing excess food calories as fat.  Structural Component o Cellulose provides support within plant cell walls o RNA/DNA store genetic information  Cell Recognition and Signaling Molecules o Immune system identifies foreign invaders by detecting different carbohydrates on the surface of the cells o Carbohydrates on blood cells to determine blood group o Sperm and egg fertilization believed to involve carb-to-carb interactions 

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Module 8: Lipids -

Identify the basic structure and function of carbohydrates, lipids, and proteins - Lipids- fats, hydrophobic, nonpolar - Characteristics of Lipids  Non-polar  Hydrophobic, insoluble in water - Functions of Lipids  Energy store for long term use  Insulation from the environment  Building block of many hormones  Fats and oils  Triglycerides- made of three fatty acids attached to one glycerol o Fatty acids are usually 16-22 carbons long o Omega-3 are kinked and act as an oil o Full hydrolysis of a fat molecule should yield three fatty acids and one glycerol.  Fats are mainly energy storage and insulating molecules o Contain twice as much energy as carbohydrates  Saturated and Unsaturated fats o Saturated- C-C bonds are single bonds and each C is bonded to 2 or 3 H atoms (each C is ‘saturated’ with hydrogen)  Solid at room temperature o Unsaturated- 1, 2, or 3 double bonds along carbon, less hydrogen bent carbon chain  Aka oils, liquid at room temperature  Phospholipids- contains only two fatty acids attached to a glycerol, which is bound to a phosphate group  Hydrophilic head, hydrophobic tail  Form membranes with other molecules that surround the cell and intracellular organelles such as mitochondria

Cell membrane is a fluid, semipermeable bilayer that separates the cell’s contents from the environment  Phospholipids with more unsaturated fatty acids can maintain fluidity at lower temperatures Steroids  4 fused carbon rings  Includes hormones and cholesterol  Cholesterol is used to build steroid hormones and is also the precursor to vitamins D and K Waxes  Protective layer on plants and animals  Prevents water from evaporating off the plant surface o

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Module 9: Proteins -

Identify the basic structure and function of carbohydrates, lipids, and proteins - The most functionally diverse group of biomolecules we will examine in this unit - Can be found in animal products as well as plant products - Also found in many toxins - Macromolecules built from amino acids  Function determined largely by the types of amino acids in the protein  Protein looks like a string of beads with each bead representing an amino acid  Bond between amino acids is called a peptide bond  Amino acids are folded  Temp and pH cause unfolding and denaturing  Amino acids with nonpolar side changes are driven into the central core of the protein because they are repelled by the water  Aka hydrophobic effect - Enzymes- proteins that catalyze reactions  Accelerate the rate at which chemical reactions take place in a cell  Reduce activation energy of the reaction  Bonding site = active site  Amino acids that bind to substrate and aid in its conversions  Many end in -ase  Not altered by the overall reaction - Storage, replication, transmission, and regulation of genetic information - Move substances in and out of the cell - Transport materials throughout the body - Facilitate mechanical movement - Maintain structure in an organism - Antibodies help protect your body from harmful invaders

Module 10: Nucleic Acids -

Compare and contrast the structure and function of the nucleic acids RNA and DNA - Nucleic acids are macromolecules that carry out two main functions: storage of genetic information and synthesis of proteins - Nitrogenous bases have either 1 or 2 rings - Phosphates are the same - DNA- the genetic material that stores information for making protein in all living organisms  Nitrogenous bases: adenine, guanine, cytosine, thymine  Sugar: deoxyribose

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 Nucleotides contain 1 phosphate  Two polymers or strands  Strands run anti-parallel  Bases are in the interior of the helix  A pairs with T, G pairs with C  Remains in the nucleus RNA- transmits the information coded in the DNA so that it can be used to produce proteins  Thymine is replaced by uracil  Sugar: ribose  Nucleotides contain 1 phosphate  Involved in protein synthesis  Leaves the nucleus  Usually single stranded  C-A, U-G...