Biology Final
Biology Semester 1 Final Study Topics
Need to know periodic table has metals, non-metals, and metalloids
Scientific method: Steps in general order (some steps need to be repeated; hence, this is called a "non-linear" process):
Observation
Question
Research
Hypothesis
Experiment
Analysis
Conclusion
Report
When you see a problem to study, consider what would be your independent variable (causes an observable effect) and dependent variable (is affected by the other variable; the changes you observe)
Macromolecules (briefly introduced in unit 1) - non-metals bonded together - covalent bonds which means valence shell electrons are shared and those electrons do the bonding, since the molecules aren't ionic - this affects the way the molecule behaves; called molecule (covalent bonds) versus being called a compound (ionic bonds); make up all organisms; macromolecule - big compound of nonmetals bonded to nonmetals with covalent bonds
Only water, HZO, is so uniquely polar (partial negative at O, partial positive at H's); cohesion - water's partial charges allow its molecules to cling to each other - ex. water can go slightly above the rim of a glass without spilling over; adhesion - lets it "crawl up" a xylem root cell against gravity
Macromolecules are divided into 4 classes (Unit 2)
Ex. what macromolecules are in spaghetti and meatballs and cheese and sauce - carbs = pasta; protein = meatballs; nucleic acids = tomato sauce; lipids = cheese
Carbohydrates - polysaccharides made from monosaccharide monomers (monosaccharide = 1 sugar, disaccharide = 2 sugar, polysaccharide = 3+ sugars)
CARBOHYDRATES I formed from monosaccharide monomers by glycosidic bonds (a type of covalent bond)
Uses elements CHO
formed through dehydration synthesis
Dehydration synthesis = taking out H from one molecule an OH from another molecule to form H,O - water - to free up spots for those two molecules to bond together, getting rid of a molecule of water in the process (losing water is called dehydration)
Hydrolysis = putting that H,O molecule back in so as to break down the polysaccharide into smaller saccharides
Disaccharide = 2 monosaccharides together; Polysaccharide = 3+ monosaccharides together
Polysaccharide examples: amylopectin = long branched; amylose = coiled, unbranched; starch = amylopectin + amylose; cellulose = long straight chains with strong hydrogen bonds to support structure (it is found in cell walls); glycogen = highly branched
Glucose C,H,20, is important since all life uses it to create ATP (adenosine triphosphate); original source of glucose: created through plants doing photosynthesis (making their own food from sunlight), so the sun is the ultimate source of all energy
Glucose: simple sugar (monosaccharide); broken down during glycolysis (step 1 of the 3-step aerobic respiration)
Proteins - several structural and body functions - includes enzymes; amino acids = monomers
PROTEINS I formed from amino acid monomers by peptide bonds (through dehydration synthesis)
Uses elements CHON
7 classes of functions: (1) contractile; (2) defense; (3) structural: (4) digestive enzymes; (5) transport; (6) hormones; (7) storage
4 levels/tiers of structural organization: (1) primary - most basic, has amino acids bonded together; (2) secondary - begins to show more structure, either as alpha helix (a-helix) or beta pleated sheet (ß-pleated sheet), attracted through bonds between R groups; (3) tertiary - a string of a-helices and ß-pleated sheets together; (4) quaternary - most complex, has multiple tertiary level strings grouped together
Proteins can be denatured (broken down into monomers) by unfavorable environmental changes - ex. change in temperature or in pH (too acidic or too basic)
Enzymes: class of protein
Act as biological catalyst (- speeds up a reaction)
Substrates are a "puzzle piece" molecule to fit into an active site "hole" to make the enzyme perform a specific function
Inhibitor - a different chemical that attaches to the enzyme in order to stop the substrate from doing its job - a non-competitive inhibitor attaches at a non-active-site place on the enzyme called an allosteric site; whereas a competitive inhibitor attaches in the same place as the substrate and tries to fill the hole first and block the substrate that way
Lipids - fats
LIPIDS I formed from fatty acid monomers by ester bonds
Uses elements CHO
Always insoluble in water
Fats, oils, waxes, hormones, steroids (ex. cholesterol, estrogen), etc
Phospholipid = 1 phosphate group + 1 glycerol + 2 fatty acid tails
Triglyceride = 1 glycerol + 3 fatty acid tails - dehydration synthesis
Fatty acids can be saturated (no room to squeeze extra Hydrogen into the carbon chain) or unsaturated (at least one double bond between carbons, causing fewer Hydrogens to attach to the carbon chain)
Nucleic acids - DNA (deoxyribonucleic acid) and RNA (ribonucleic acid); in the nucleus since the function of the nucleus is to control everything within the cell, and DNA is how it does that (genetic code) - instruction manual for all functions within the cell
NUCLEIC ACIDS I formed from nucleotide monomers by phosphodiester bonds (*but hydrogen bonds form between nucleotides to hold them together within a DNA double helix)
Uses elements CHONP
Also found within nucleolus since the nucleolus functions to create ribosomes which in turn make proteins <see Unit 3 notes below> using rRNA (ribosomal RiboNucleic Acid)
Cell Theory (Unit 3)
History of the cell/cell theory from 6 contributing scientists:
Zacharias Jansen: 1590 - created first compound microscope
Robert Hooke: 1665 - viewed cork under microscope, named "cells" he saw
Anton van Leeuwenhoek: 1670s - better microscope, viewed "animalcules" (microorganisms)
Matthias Schleiden: 1838 - all plants are made of cells
Theodor Schwann: 1839 - all animals are made of cells
Rudolf Virchow: 1855 - all cells come from preexisting cells
Cell Theory Components
1) All organisms are composed of one or more cells
2) The cell is the basic unit of structure and organization in organisms (aka The cell is the basic unit of life)
3) All cells come from preexisting cells
Cells (Unit 3)
Levels of organization of the components of living things from smallest to largest:
Cell - most basic unit of life
Tissue - group of similar cells that work together
Organ - group of tissues that perform a specific function
Organ system - group of organs with related functions
Organism - living thing carrying out basic functions of life
Eukaryote = multicellular organism with a nucleus in each cell, can be either animal or plant cells; Prokaryote = single cell organism without a nucleus, includes bacteria
Parts of the cell: animal cells A, plant cells P, or both B; or prokaryote K
Cell wall - P - protective barrier made of cellulose, helps plant cells to hold their shape even when turgid (overstuffed with water)
Cell membrane - B - flexible barrier that controls what goes in and out of a cell
Capsule - K - another protective coating, outside the cell wall, for some bacteria
Nucleus - B- porous sphere containing all DNA in the cell
Nucleolus - B - small organelle inside a nucleus, makes ribosomes
Ribosome - B - small organelle that makes proteins; can be free floating in cytoplasm or attached to RER
Rough endoplasmic reticulum (RER) - B - creates proteins
Smooth endoplasmic reticulum (SER) - B - creates lipids and carbohydrates
Golgi Apparatus/Golgi Bodies - B - the cell's "mail carrier:" processes and packages proteins, lipids, and carbohydrates in order to send them out of the cell
Centrosome (made up of 2 centrioles) - A - a pair of perpendicular centrioles; contains spindle fibers to help a cell carry out cell division; each centriole is a cylinder of 9 triplets of microtubules
Mitochondrion - B - where aerobic respiration takes place; breaks down food (glucose) into energy (ATP), called the powerhouse of the cell
Chloroplast - P - where photosynthesis takes place; uses light to make glucose from water and carbon dioxide, makes oxygen
Vacuole - P - a fluid-filled sac to store food, water and waste; *animal cells sometimes can form a temporary vacuole, but they are a large and permanent organelle in plant cells
Lysosome - B - digestive enzymes inside help it break down polymers into monomers, sometimes for recycling to use them again
Cytoplasm - B - "cell goo," gel-like substance that fills a cell and holds/supports the cell's organelles
Flagellum - K - tail stuck to some prokaryotes to help them move
Cell transport - structure and functions of cell membrane (Unit 4)
Cell membrane has many special proteins making it up:
Hydrophilic (water-loving) head - phospholipids as outside layers of the bilayer membrane structure
Hydrophobic (water-hating) tails - make up the middle of the bilayer
Glycoprotein - can be used to recognize the cell
Glycolipid
Integral protein - embedded within the membrane
Transmembrane protein - crosses from one side of the membrane to the other, through the hydrophobic middle
Receptor protein - transmembrane with a receptor at each end to transmit signals to/from the cell
Channel protein - allows smaller polar molecules to travel through
Carrier protein - "swallows" bigger molecules to allow them through
Peripheral protein/surface protein
Cholesterol - regulates fluidity
Cell membrane is a fluid mosaic
4 main functions of cell membrane:
1) Transport - move things in and out
2) Cell adhesion - stick cells together (needed to form tissues)
3) Cell recognition - uses signals to recognize a cell
4) Cell signaling - send messages with other cells
Active transport - requires energy to work
Macromolecules taken in/out through:
Endocytosis = part of the cell membrane surrounds a large molecule and breaks off from the rest of the membrane to form a new temporary vesicle inside the cell, using the cell membrane as the new vesicle membrane instead - vesicle can then open up and allow the molecule to be inside the cell
Exocytosis = backwards from endocytosis, a vesicle surrounds a molecule and meshes in with the rest of the cell membrane, opening to place the molecule outside the cell
Osmosis - taking in water until concentrations
Photosynthesis (unit 5)
The process of using sunlight with water and carbon dioxide to create glucose inside cells of plants and other autotrophs (make their own food)
Light reactions occur inside the thylakoid ("pancake stacks") of the chloroplast - electron transport chain and photosystems (proteins which collect sunlight) and ATP synthase (enzyme to create ATP) all sit inside the thylakoid membrane I this part uses water and expels oxygen
Dark reactions (Calvin cycle) occur inside the stroma (fluid in the chloroplast that acts as the cytoplasm does in a whole cell) I this part uses carbon dioxide and creates glucose
Phloem cells in the plant can move glucose around the plant - a plant will always take its glucose to its mitochondria in order to convert the glucose it just made into energy (ATP) - this is how photosynthesis can lead directly into cellular respiration <see next>
Leaf = major photosynthetic organ of a plant - where the sun hits, where the chlorophyll (pigment to absorb light into the chloroplasts) is concentrated
Cellular respiration (unit 5)
The process of breaking down glucose in order to create ATP aka. adenosine triphosphate (ATP = energy "currency" of life) in both autotrophs and heterotrophs (eat food to survive)
Aerobic respiration - uses oxygen to break down the glucose; creates a LOT of energy (ATP)
Both aerobic and anaerobic respiration begin with step #1 glycolysis in the cytoplasm of the cell - glycolysis breaks down glucose into more manageable compounds that can run through the process of converting ADP to ATP
Aerobic respiration = occurs in the mitochondrion: step #2 is Krebs cycle, in the inner matrix (inside the inner membrane); step #3 is electron transport chain, across the inner membrane - step #3 makes a LOT of ATP
Ethanol fermentation and lactic acid fermentation occur in the absence of oxygen (called "anaerobic respiration") - the cell is able to make energy from glucose this way, but these methods are far less efficient than aerobic respiration and therefore do not produce as much ATP
Same step #1 (glycolysis) but different step #2/3
Ethanol is alcohol, and fermentation means it's creating alcohol under the conditions of no oxygen - breakdown of glucose yields ethanol and carbon dioxide in this process I plant fruit does this method of anaerobic respiration, but animals do not do this
Lactic acid is a biproduct that makes your muscles sore after exercise; lactic acid fermentation breaks down glucose without oxygen and creates lactic acid I animals do this when not enough oxygen is breathed in to supplement the energy required (rigorous exercise) collect sunlight) and ATP synthase (enzyme to create ATP) all sit inside the thylakoid membrane I this part uses water and expels oxygen
Dark reactions (Calvin cycle) occur inside the stroma (fluid in the chloroplast that acts as the cytoplasm does in a whole cell) I this part uses carbon dioxide and creates glucose
Phloem cells in the plant can move glucose around the plant - a plant will always take its glucose to its mitochondria in order to convert the glucose it just made into energy (ATP) - this is how photosynthesis can lead directly into cellular respiration <see next>
Leaf = major photosynthetic organ of a plant - where the sun hits, where the chlorophyll (pigment to absorb light into the chloroplasts) is concentrated