General Biology - Review Sheet for Exam | BIOL 1005, Study notes of Biology

Download General Biology - Review Sheet for Exam | BIOL 1005 and more Study notes Biology in PDF only on Docsity! Bio lecture one  Three largest groups that biologists place organisms in are: 1. Bacteria 2. Archaea 3. Eukarya  Viruses are not in the classification scheme because they do not have characteristics like other organisms -cannot reproduce by themselves  The scientific theory is different from theories from other fields 1. General explanation of important phenomena 2. Formed from repeated observations and experiments that support it 3. May be modified if new evidence emerges 4. More general than a hypothesis  Evolution the unifying theory of biology 1. Arises as a consequence of genetic variation 2. Heritance of variation by offspring 3. Natural selection  Chemical Bonds 1. Attractive forces that hold atoms together 2. Focused on sharing, losing, or gaining electrons  Polar Covalent Bonds 1. Sharing of bonds 2. Unequal sharing- pulls on the stronger atom  Nonpolar Covalent bonding 1. Equal sharing  Hydrogen Bonding 1. Important in water 2. A bond between the hydrogen of one polar molecule and the opposite charge on an atom from another molecule 3. Not as strong as covalent bonding  Ionic Bonds 1. Based on gaining or losing electrons 2. Create an ion- an atom that has a charge that is different from its usual state ( positive or negative) 3. Easier to break than a covalent bond  Importance of water 1. Made from polar covalent bonding between hydrogen and oxygen 2. Organisms contain 60-90% water 3. 75% of the Earth’s surface is water 4. Life probably originated in water 5. Water has unique properties essential for life 6. A good solvent- proteins, salts, sugars, other polar molecules, oxygen, carbon dioxide, glucose Bio lecture 2  Ice: an unusual solid 1. Water is most dense at 4 degrees Celsius 2. When ice is on the top of the pond, water is warmest at the bottom of the pond, because its more dense  Water moderates the effects of temperature changes 1. Warms up much more slowly than land does- water cold in early summer 2. Cools down slower than land- water warm in fall 3. Due to hydrogen bonds- need to be broken in order to have water molecules to be broken  Evaporative cooling 1. Hydrogen bonds cause water to have a higher evaporation 2. Sweating is meant to cool you down- heat energy is released when hydrogen bonds break  Water is very cohesive 1. Water molecules stick together- hydrogen bonding 2. Cohesion creates surface tension- certain animals can run on water without breaking the hydrogen bonds 3. Cohesion is also important in transporting water in plants  Water molecules split into hydrogen ions and hydroxide ions- split apart and then reform 1. Oxygen keeps the electron H 2. Hydrogen ion is H+ 3. If not in pure water, breaking apart may vary- may turn into acids or bases  PH 1. Acids are <7 2. Bases are >7 3. 7 is neutral 4. The more acid the substances- the higher the concentration of hydrogen ions 5. PH is merely the measure of hydrogen concentrations 6. Logarithmic scale- multiplies by the power of ten  PH and life 1. Homeostatic conditions in an animal’s body- body is constantly working to keep its homeostatic PH level 2. Water organisms have range of PH- if PH becomes too harsh, they can be threatened 3. There are buffers to help regulate PH- can take up hydrogen protons or release them to help moderate PH changes 4. The buffer is a chemical- bicarbonate in humans- to help balance out the hydrogen ions  Biological molecules 1. Also referred to as organic compounds- contains carbon and some hydrogen 2. Carbon skeletons can be chains or rings  Protein denaturation 1. Alteration of secondary and tertiary structure of a protein 2. Environmental activities can be the cause 3. Heating or cooling too much can change the way that the amino acids stay connected 4. PH is important for protein structure  Nucleotides and nucleic acids 1. Store information in the genetic code a. DNA 2. Participate in protein synthesis a. RNA 3. Energy carriers a. ATP 4. Nucleotides are monomers: three parts a. Phosphate group b. Sugar group c. Nitrogen containing base molecule 5. ATP a. A nucleotide based molecule b. Has three phosphate groups c. A monomer of just one of the nucleotides  Cell membrane structure and function 1. Single celled organisms have all characteristics of life in its one cellular structure 2. Functions a. Isolates the cell contents b. Regulates exchange c. Communicates with other cells d. Creates attachments to hold the cell together e. Regulates reactions that take place inside the cell Bio lecture 5  Lipid molecules 1. Head is hydrophilic 2. Tails are hydrophobic 3. To keep the hydrophobic tails away from water, lipids connect themselves together, tails to the inside so they do not get water on them 4. They are not bonded but flexible  Proteins 1. Are embedded in the fluid phospholipic bilayer 2. Called the fluid mosaic model- proteins are blue in the model, lipids yellow 3. Have carbohydrates attached to proteins  Membrane components 1. Phospholipids a. isolate cell contents 2. Cholesterol a. animal cells b. stronger, more flexible 3. Proteins and glycoproteins a. Transport b. Receptor c. Recognition d. Attachments  Membrane transport 1. Passive a. Simple diffusion b. Facilitated diffusion c. Osmosis d. No energy required 2. Energy requiring transport a. Active transport b. Exocytose c. Endocytosis  Diffusion 1. A passive process that happens whenever there is a radiant between one substance or another 2. The movement of molecules down a concentration gradient 3. Can be affected by temperature a. Moves faster  Simple diffusion 1. Certain molecules can pass through the phospholipic bilayer because of the concentration gradient 2. Cell does not have to expend any energy for that to happen- passive 3. Two kinds of proteins that allow for passive movement through them a. Channel proteins- allows ions to move through it based on its concentration gradient b. Carrier proteins- will change shape with the right molecule that enters it  Osmosis 1. The movement of water across a membrane 2. The movement of water down its own concentration gradient  Hypertonic solution 1. Hyper= greater 2. The solution on the outside has a greater concentration gradient 3. Loses volume because the water is trying to balance the concentration gradient 4. Cell shrivels up because all of the water left cell  Hypotonic solution 1. Hypo- less 2. The solution saturates the cells to almost the point of bursting 3. Cell swells up because it is filled to the brim with liquid  Plant cells 1. Have a cell wall 2. Wants the inside of the cell to take up excess water 3. The outside is always going to be hypotonic because the cell sucks in enough water 4. The pressure that the inside of the cell puts on the inside of the cell wall causes the leaves and stems to be stiff and strong (healthy) 5. When water is scarce, the pressure is less and the plant will wilt 6. Plant cells are isotonic- constantly balancing the water going in and out of the cell wall Bio lecture 6  Active Transport 1. Active transport proteins are sometimes called pumps 2. Gives the active energy to go against the grain of the protein 3. Uses up ATP to accomplish this transport 4. Energy used by the ATP is used to change the shape of the protein so that it can move the ion  Endocytosis 1. The mechanism for bringing materials into the cell 2. Require energy to carry out the process 3. Usually used when the materials used to be transported are in large quantities 4. Sometimes requires receptors for materials to be brought into the cell 5. Phagatosis- cells ingesting bacteria (white blood cells)  Exocytosis 1. The mechanism for bringing materials out of the cell 2. Requires energy to carry out the process 3. Usually used when the materials used to be transported are in large quantities 4. Used in the human body to secrete body fluid 5. Creates a vesicle that fuses with the outer cell membrane that dumps its contents to the outside of the cell  Cell Junctions 1. Hold cells together 2. Cell to cell communication 3. Desmosomes a. connect cells together and are found in places that stretch a little bit 4. Tight junction a. protein connecters hold the two adjacent cells together tighter b. “leak proof” for places that need it like kidneys 5. Gap junction 2. Transport work b) Endoplasmic cytosis 3. Chemical work  Two types of energy 1. Potential a) Chemical energy concentrated- stored in a chemical bond 2. Kinetic b) Motion energy  First law of thermodynamics 1. Law of conservation of energy 2. Cannot create it or destroy it  Second law of thermodynamics 1. The amount of useful energy decreases with every conversion 2. Entropy- a measure of disorder  Chemical reaction 1. A process that forms and breaks chemical bonds that hold atoms together 2. Reactants form products 3. Exergonic reaction- energy goes out of the reaction 4. Activation energy- initial energy input in order to get a reaction started 5. Endergonic reaction- energy must come into the reaction in order for it to work (photosynthesis) 6. ATP synthesis- energy stored in ATP is used a) Take ADP plus phosphate and ATP energy is released b) ATP is constantly being recycled c) Once ATP is used, the process flips around and goes backwards d) Constantly in a cycle 7. Coupled reactions- glucose breakdown and protein synthesis 8. Coupled reactions are Exergonic- less energy than it began with- some energy is going to be converted into heat 9. Catabolic reaction- breakdown reactions (metabolism) 10. Anabolic reaction- synthesis reactions  Metabolism 1. Sum total of all the chemical reactions in a cell 2. Refers to how your cells are using energy 3. Take place as a series of small reactions 4. Added together these small reactions create the metabolic pathways 5. Can interconnect with each other 6. some pathways are cyclic- end up where it began  orderly cell metabolism is maintained by 1. enzymes 2. coupled reactions 3. energy carrier molecules available to move energy around  catalysts 1. speed up reactions 2. only those reactions that would occur spontaneously 3. not consumed or changed in a chemical reaction Bio lecture 10  Energy for cellular work - Heterotrophs vs. autotrophs - Fats, carbs, and proteins can be metabolized - Focus on glucose metabolism  Glycolysis: sugar splitting - 2 parts o glucose activation o energy harvest - Products o 2 ATP o 2 NADH o 2 pyruvate  Anaerobic metabolism - Glycolysis + fermentation - 2 types of fermentation o Alcohol fermentation o Lactate fermentation  Alcohol metabolism - Alcohol is absorbed into the blood - Metabolism occurs in the liver - Speed of alcohol metabolism varies - Limited by enzyme availability - Blood Alcohol content - Alcohol is a CNS depressant Bio lecture 11  Pigments 1. The molecules are clustered together in membranes that are inside of chloroplasts 2. The clusters are called photosystems 3. The pigments capture light and funnel it to the reaction center (we see green) 4. Electron transport chains- series of proteins imbedded in the membranes next to the photosystems 5. When an electron gets excited from its normal position, it goes back, but gives off heat and light as energy 6. When this happens to chlorophyll, it looks red 7. The excited electrons are captured by the Electron transport chain 8. Energized carriers are formed-NADPH and ATP 9. Light dependent reactions use: a) Solar energy b) Water  Calvin-Benson cycle 1. The name of the cycles of light dependent and light independent reactions 2. Also called the C3 cycle 3. Breaks into three parts a) Carbon fixation - RUBP (five carbon sugar) - Rubisco (enzyme) b) Synthesis of G3P (three carbon sugar) - Uses energy from ATP and NAPDH - G3P is used to make glucose c) Regeneration of RUBP - Requires energy to carry out this last phase - Returns the cycle to the beginning 4. Glucose is a much more versatile compound for storing energy than NADPH 5. Sugar is the product of the Calvin-Benson cycle  Links to life: 1. You owe your life to plants - They produce oxygen - Energy molecules- need carbon compounds Bio lecture 12  Cellular respiration - Aerobic pathway that follows glycolosis - 3 parts to cellular respiration o Acetyl Co-A formation  2 NADH o Krebs cycle  6 NADH  2 FADH2  2 ATP o Electron transport  32-34 ATP  Oxygen is needed here for cell respiration  What is EPO? - Erythropoietin by kidneys o Hormone produced by kidneys Bio lecture 15  How are genes and proteins related? - Genes determine specific characteristics of an organism - Proteins are a cell’s “molecular workers” - Beadle and Tatum o Hypothesis: genes might encode enzymes o “one gene one enzyme” hypothesis o A mutation in a single gene affected a single enzyme in a single biochemical pathway o Nobel prize- 1958 o Problem with hypothesis: proteins function more than just by producing enzymes- needs to be modified- “one gene one protein”  Two steps from gene to protein - Transcription- takes DNA to RNA - Translation- takes RNA to protein - A gene is a segment of DNA that can be transcribed  RNA structure - A single stranded nucleic acid - Ribose sugar - Uracil instead of thymine  Types of RNA - Messenger RNA (mRNA)- carries the code from DNA (in nucleus) to ribosomes - Ribosomal RNA (rRNA)- makes up ribosome - Transfer RNA (tRNA) - delivers amino acids to the ribosome - All are made during transcription  How do we translate? - The Genetic Code o Triplet Code- 64 possible code words o mRNA triplets = Codons o nearly universal in all organisms Lecture 16  What is the promoter region? - a region of a parent DNA strand that binds to the RNA polymerase and initiates transcription  order of events: - (6) transport to cytoplasm - (1) RNA polymerase binds to promoter - (3) Termination signal is read at the end of the gene - (5) mRNA transcript is cut and spliced - (2) RNA polymerase elongates RNA molecule - (4) DNA rewinds into a double helix  During Translation elongation - mRNA codons and tRNA anticodons pair bases - Amino acids are joined by peptide bonds Lecture 17  Mutations - Only 21 thousand genes - Changes in the base sequences of DNA - Somatic cell vs. germ cell mutation - Differences in whether the mutation is passed on by reproduction or not  Consider this: - Each human cell contains the same set of genes - Human body = about 200 different cell types - A fraction of the genes are expressed in each cell (specialized genes) - Differential gene expression results in specialized cells  Transcription regulation in eukaryotes - Regulatory proteins/ transcription factors - Some require activation - Condensed regions of chromosomes = so tight together that genes cannot transcribe - Chromosome inactivation o Barr body- inactive X chromosome  Anthocyanin - Flavored pigments in plant cells that make them look red, purple, or blue - Anthocyanin is synthesized by the enzyme UFGT - Green grapes lack anthocyanins due to a mutation in the MYB transcription factor - Which step in the UFGT expression pathway would be affected by mutation In the MYB transcription factor? o positioning and activation of RNA polymerase  What is a gene? - Located at a particular place on a chromosome - A segment of DNA that can be transcribed (RNA) - Transcription of protein coding genes produces mRNA that can be translated into a protein New unit lecture one  Karyotype of human male - In homologous pairs - Homologues are one pair - Diploid- cells that have homologous pairs (2n) - Haploid- a set of chromosomes containing only one chromosome pair (n) - Autosomes- chromosomes that are the same in male and females of species - Sex chromosomes- chromosomes that are not the same in male and females of species  What are the correct sequence of events in mitotic cell division - (3) Sister chromatids are pulled apart by the spindle fibers (anaphase) - (1) chromosomes visible in nucleus (prophase) - (4) New daughter nuclei form (telephase) - (2) Chromosomes line up at the cell equator (metaphase) - (5) cytokinesis (cell division)  the center of the cell is referred to as the cell equator  spindle microtubules line up the chromosomes and later pull the sister chromatids apart  free spindle microtubules are actually stretching so that the cell is bigger  cytokinesis - not really a stage of mitotic division - cytokinesis is the division of the nuclear membrane - in animal cells, the cell is pinched in - in plant cells, the cell plate is formed (little vesicles that are filled with carbohydrate and form on the cell equator) - these vesicles fuse together and once fusion is complete, we have a new cell membrane  summary of mitotic cell division - results in two daughter cells - exact copies of parent cell - if the cell is diploid then the daughter cells will be diploid - if the cell is haploid then the daughter cells will be haploid - growth, repair, replacement, asexual reproduction  Eukaryotic cell cycle - Most of the life of cell is spent in interphase - If division is necessary, then the cell with go through stages S, G2, and then cell division - Unregulated cell division can lead to cancer  Control of the cell cycle - Three checkpoints o G1 to S- is the DNA intact  Growth factors are released into the extracellular fluid and they attach to growth factor receptor  Cyclin- activates Cdk; active Cdk stimulates DNA replication  Will trigger G1 to S (stimulates DNA replication)  If DNA damage prevents G1 to S- gene p53 is triggered to synthesize its proteins and blocks the action after Cdk  Gene p53 prevents DNA to continue to divide if the cell is damaged o G2 to M- has the DNA replication taken place and done accurately o Metaphase to anaphase- are all of the chromosomes aligned at the equator - Protein regulators drive the cycle - Random fertilization o Genetically unique eggs join with genetically unique sperm o 8 million X 8 million = 64 trillion possibilities  Which of the following occurs during anaphase 1 of meiosis o Homologous pairs separate  The cells of the intestinal epithelium are continually dividing, replacing dead cells lost from the surface of the intestinal lining. If you examined a population of intestinal epithelial cells under the microscope, most of the cells would be in what stage? o Interphase  Human genetic traits - Blood type (A, B, AB, O) - Rh factor (Rh +, Rh-) - Tongue rolling - Widow’s peak - Hitchhikers thumb - Detached earlobes  Genes terminology - The location of a gene on a chromosome is its locus - Homozygous- two identical genes with the same alleles - Heterozygous- two genes with two different alleles - Hybrid- formed from mating individuals with two different traits- will be heterozygous traits  Mendel - The father of genetics - Studied the pea plant - Cross pollinating different colored flowers were some of the experiments that he did - Parental generation- always true breeding o All offspring were purple flowers o The F2 generation had offspring that were 3/4 purple and ¼ white - Law of segregation o Two alleles of a gene segregate from one another at meiosis o Offspring receive one allele from each parent - Phenotype- the physical expression of genes - Genotype- the combination of alleles that these plants produce - Punnett square- a tool to find out how to determine the genotype Lecture 3  Punnett squares - Phenotypic ratio- the ratio of one color to another - Genotypic ratio- the ratio of dominant vs. recessive  Dihybrid cross - P generation: o Smooth yellow (SSYY) o Wrinkled green (ssyy) - F1 generation o 100 % smooth yellow (SsYy) - F2 generation o New combinations o Had smooth yellows, smooth greens, wrinkled yellows, and wrinkled greens o Phenotypic ratio was 9:3:3:1 - Law of independent assortment o Genes on different pairs of homologous chromosomes o Alleles of one gene distributed to gametes independently of alleles for other genes  Genetic linkage - Inheritance of certain genes as a group - On the same chromosome - Crossing over can disrupt linkage o Recombined chromatids  Sex determination - The male parent determines the gender of the offspring - The X chromosome has a lot to do with things other than sex determination - Y chromosome is not as diverse - Sex linked genes o Found only on X or Y chromosomes o Sex linkage affects inheritance o 1st case to be discovered was in fruit flies:  Eye color in Drosophila  White eyed male X true breeding red eyed females  100% F1 red eyed  Experiment done by Thomas Morgan  This gene for eye color is on the X chromosome  For X linked traits, males are more likely to demonstrate the recessive traits because females are always dominant Lecture 5  Human Genetics - Pedigrees o Allow you to study genetics in different ways o Can trace character habits and disorders in families  Human Genetics disorders - Autosomal recessive - Autosomal dominant - X linked (sex linked) recessive - Tay Sachs Disease o Defective enzyme for lipid degradation o More than 90 mutations identified o Screening available o Most common in:  Ashkenazi Jewish population  Cajun subpopulation in southern LA  French Canadian subpopulation - Other Autosomal dominant conditions: o Huntington’s disease  Progressive degeneration of neurons  Adult onset most common o Polydactyl  More than 5 digits on hands/feet o Progeria  Premature aging  Results from new mutation - How do errors in chromosome number affect humans? o Nondisjunction  Failure of sister chromatids to separate o Genetic disorders: Nondisjunction of sex chromosomes  Turner syndrome  Trisomy X  Jacob Syndrome  Klinefelter syndrome Lecture 6  Genetic disorders: non-disjunction of sex chromosomes - Turner syndrome - Trisomy X - Jacob syndrome - Klinefelter syndrome  Screening for genetic disorders - 1. Identify carriers o Pedigree analysis o DNA analysis - 2. Gender selection - 3. Embryo screening o In vitro fertilization o Pre- implantation genetic diagnosis - 4. Prenatal testing