OAT- Biology. Study Pack. 100% Approved.

Ingestion - ✔✔Acquisition of food Assimilation - ✔✔Building of new tissues from digested food Monosaccharide - ✔✔single sugar subunit - carb Ex: glucose, fructose, galactose Disaccharide - ✔✔2 monosaccharides - car ...

Ingestion - ✔✔Acquisition of food Assimilation - ✔✔Building of new tissues from digested food Monosaccharide - ✔✔single sugar subunit - carb Ex: glucose, fructose, galactose Disaccharide - ✔✔2 monosaccharides - carb Ex: sucrose, lactose Polysaccharide - ✔✔Polymer of sugar subunits -carb - insoluble in water - Ex: glycogen, cellulose, starch Lipids - ✔✔3 fatty acids bonded to glycerol - chief means of food storage -Major component of adipose tissue -Steroids, waxes, carotenoids, poryphyrins Proteins - ✔✔Polymers of amino acids joined by peptide bonds -Hormones (ACTH & Insulin), enzymes, structure proteins (collagen), transport (hemoglobin), antibodiesEnzymes - ✔✔↓ activation E and ↑ rate of rxn - do NOT affect overall E -↑ temp : ↑ enzyme action/ optimal pH= 7.2 (except pepsin and pancreas) Competitive Inhibitors (enzymes) - ✔✔Compete with substrate for binding at ACTIVE site - can be overcome by adding more substrate -Vmax not affected Noncompetitive Inhibitors (enzymes) - ✔✔bind at allosteric site - diminishes Vmax Prokaryotes - ✔✔Bacteria -Contains ribosomes, nucleic acids, plasma membrane, nucleoid, cell wall -Lack nucleus, membrane-bound organelles, Eukaryotes - ✔✔Cell wall in fungi and plants - Nucleus, and membrane bound organelles Centrioles - ✔✔microtubules involved in spindle organization during cell division -NO membrane -plants lack centrioles Centromere - ✔✔Near middle of eukaryotic chromosomes where spindle fibers attach Lysosome - ✔✔Membrane bound -Involved in ingestion -Hydrolytic enzymes-has the ability to "commit suicide" Mitochondria - ✔✔-generate energy (oxidative phosphorylation → ATP) -self-replicating organelles -contain DNA in circular plasmids Desmosomes - ✔✔"Spot welds" -attach cells together and give cells mechanical strength -Ex: skin Tight junctions - ✔✔seal the spaces between cells and prevent cell leakage Ex: intestinal cells Nucleus - ✔✔"information center" -Contains chromosomes, DNA and RNA -Separated by a double membrane nuclear envelope Nucleolus - ✔✔Within the nucleus -Ribosome synthesis takes place Endoplasmic Reticulum (ER) - ✔✔Transport network for molecules targeted for certain modifications and specific destinations Rough ER - ✔✔Has ribosomes on its surface -secretes proteins into cytoplasm Smooth ER - ✔✔Lacks ribosomes -plays a role in Calcium sequestration and releaseRibosomes - ✔✔-RNA and protein molecules -Can be found floating freely or bound to a membrane Vacuoles - ✔✔Store food and waste -Plant vacuoles usually bigger than animal vacuoles Gap Junction - ✔✔Allows cells to exchange nutrients and for molecular communication Endosymbiotic Theory - ✔✔Mitochondria and chloroplasts originated as independent unicellular organisms living in symbiosis with larger cells Fluid Mosaic Model - ✔✔Lipids and proteins are free to move back and forth fluidly - diffuse laterally -Integral proteins: embedded in membrane by hydrophobic interactions - hard to remove -Peripheral proteins: stuck to integral membrane proteins by H-bonding or electrostatic interactions - easy to remove Cell surface receptors - ✔✔Type of integral membrane protein -3 types 1. Ligand-gated (open ion channel) 2. Catalytic 3. G-protein G-protein - ✔✔Uses secondary messengers that amplify the signal Ex: cAMP S phase - ✔✔replicate genome (create chromatids) G₁ and G₂ Phases - ✔✔Gap phasesMitosis - ✔✔2N→2N Occurs in all dividing cells 10% of cell cycle Phases of Mitosis - ✔✔Interphase: replication of genetic material →sister chromatids Prophase:chromosomes condense; spindles form Metaphase: chromosomes align at M-plate Anaphase: sister chromatids separate (shortest phase) Telophase: new nuclear membranes form (cleavage furrow forms); spindles disappear Sequence of Mitosis - ✔✔S phase →G₂→P→M→A→T→G₁ Meiosis - ✔✔Occurs in sex cells -Homologous chromosomes pair at meta plate (tetrads) -Crossing over can occur - 2N → N Phases of Meiosis 1 - ✔✔Meiosis 1: produces 2 daughter cells with N chromosomes with sister chrom -P1: crossing over occurs -M1: Tetrads align at M-plate (synapsis); each pair attaches to separate spindle -A1: homo. pairs pulled to opposite poles (disjunction) - distribution of 2 daughter cells is random with respect to parental origin -T1: nuclear membrane forms around each nucleus Phases of Meiosis 2 - ✔✔Similar to mitosis -Only 1 daughter cell becomes a functional gamete in females (the rest are polar bodies) Chiasmata - ✔✔X-shaped region with different chromatids of homo. chromosomesKinetichore - ✔✔Specialized group of proteins and DNA on a chromatid to which several spindle microtubules are attached - found within the centromeres of each chromosome Synapsis - ✔✔Pairing of homo. chromosomes in Meiosis 1 Inversion - ✔✔chromosomal segment turned 180⁰ Translocation - ✔✔2 non-homo. chromosomes interchange genes Nondisjunction - ✔✔failure of homo. chromosomes to separate during Meiosis 1 or sister chromatids in Meiosis 2 - results in trisomy or monosomy Asexual Reproduction - ✔✔-Binary fission -Budding -Regeneration -Parthogenesis Binary fission - ✔✔Prokaryotes - DNA replicates and cell wall grows inward along midwall -Ex: paramecia, amoebae, algae, bacteria Budding - ✔✔Develops an outgrowth - forms a smaller cell - Ex: hydra and yeast Regeneration - ✔✔Regrowth of lost body part Ex: hydra and starfishParthogenesis - ✔✔Unfertilized egg → adult Ex: bees and ants Gonads - ✔✔Male: testes Female: ovaries Leydig cells - ✔✔In the testes -Secrete testosterone Spermatogensis - ✔✔Sperm production in seminiferous tubules - head = nucleus -tail = flagellum Acrosome - ✔✔membrane-bound structure at ant. end of sperm cells -contains hyaluronidase (breakdown of protective surfaces of egg) Prostatic Fluid - ✔✔helps neutralize the acidic vaginal secretions to enhance sperms' ability to swim - also neutralizes seminal fluid Oogenesis - ✔✔oocytes produced in ovaries Capacitation - ✔✔functional maturation of the spermatozoa while in the female -allows for egg penetration Male Reproductive - ✔✔path of sperm: SEVEn UP -seminiferous tubules → epididymis→ vas deferens→ ejaculatory duct→ nothing → urethra → penisFemale Reproductive - ✔✔Fallopian tube → Uterus → Cervix → Vaginal canal Menstrual Cycle - ✔✔-Follicular: FSH promotes development of follicle which secretes E -Ovulation: peak in E → ↑ LH → ovulation → mature follicle bursts releasing ovum - Luteal: LH induces follicle to develop into corpus luteum which secretes E and P (LH and FSH inhibited) - Menstruation: if fertilized, placenta produces hCG (E and P levels remain high) If not fertilized, corpus luteum atrophies (drop in E and P) and menses occurs Estrogen - ✔✔Hormone - thicken endmetrium -secreted by corpus luteum Progesterone - ✔✔Hormone -Development and maintenance of endometrial wall -Secreted by corpus luteum Gametophyte generation - ✔✔Haploid (N) - produce haploid gametes (mitosis) - sexually reproduce Ex: mosses Sporophyte generation - ✔✔Diploid (2N) - produces haploid spores by meiosis Ex: ferns and angiosperms Angiosperm - ✔✔-Flowering plants Parts of a flower - ✔✔-Stamen: male organ; stalk-like filament and sac-like anther (pollen)-Pistil: female organ; composed of stigma (catches pollen), style and ovary -Sepals: green leaves that cover flower during early stages of development Flower fertilization - ✔✔1 sperm nucleus + 1 egg nucleus → zygote → embryo 1 sperm nucleus + 2 polar nuclei → 3n endosperm Seed formation - ✔✔- Epicotyl: precursor of leaves - Cotyledons: seed leaves - Hypocotyl: lower stem and root -Endosperm: feeds embryo -Seed coat: outer covering of ovule Incomplete dominance - ✔✔blends of parental phenotypes ex: red and white snapdragons = pink snapdragons Codominance - ✔✔multiple dominant alleles -ex: blood Sex-linked recessive - ✔✔gene carried on X chromosome Ex: hemophilia and color blindness Epistasis - ✔✔When 1 gene masks or modifies the expression of another gene Pleiotrophy - ✔✔single gene effects several phenotypic characteristics Mutations - ✔✔Somatic cells → tumors Gametes → transmitted to offspring Types of mutations:- insertion, deletion, substitution Pyrimidines - ✔✔CUT the PY - 1 ring - ↑ G/C more stable because G is triple bonded to C Redundancy/degeneracy - ✔✔genetic code synonyms - multiple codons for the same aa Nucleoside - ✔✔sugar + base Protein synthesis - ✔✔Replication → transcription → translation Replication: DNA → DNA in 5'→3' Helicase: unwinds double helix Primase: begins replication Transcription: DNA → RNA m-RNA has inverted complementary code Translation: RNA → Protein m-RNA→ aa Exons - ✔✔nucleotide base sequences that are transcribed into mRNA→proteins Introns - ✔✔Removed during transcription - exons = don't exit mRNA - ✔✔carries complement of DNA from nucleus to ribosomes - least abundant RNArRNA - ✔✔ribosomal RNA - most abundant form of RNA tRNA - ✔✔brings aa to ribosomes during synthesis, recognizes aa and codons - in cytoplasm -smallest form of RNA Ribosomes - ✔✔2 subunits 3 binding sites: 1 for mRNA and 3 for tRNA PCR technique - ✔✔makes multiple DNA copies in vitro X-ray diffraction - ✔✔most accurate way to discover molecular structure Polypeptide sequence - ✔✔initiation (AUG) → elongation → termination (UAG, UGA, UAA) Gene Regulation - ✔✔Transcription enables prokaryotes to control metabolism Inducible system - ✔✔require inducer for transcription - RNA polymerase binds to promoter → structural genes transcribed - Repressor binds to operator → structural genes NOT transcribed - Inducer binds to repressor → no binding to operator → genes transcribed Repressible system - ✔✔Constant state of transcription unless co-repressor-repressor complex present to inhibit Bacteriophage - ✔✔Virus that infects host bacterium; attachment/absorption → penetration/eclipse → lytic or lysogenicLytic cycle - ✔✔phage DNA takes control of bacterium.makes numerous progeny. -bacterial cell bursts (lyses) releasing virons -called virulent - ALL HOST CELLS destroyed = evolutionary disadvantage Lysogenic Cycle - ✔✔Becomes integrated into genome in harmless way (provirus/prophage) - every time the host reproduces, the prophase is reproduced too - a stimulus can cause the prophage to go into lytic cycle and lyses Techoic acid - ✔✔used for recognition and binding sites by bacterial viruses that cause infections Cleavage - ✔✔-Results in progressively smaller cells (↑ ratio of nuclear-to-cytoplasm and surface-tovolume ratio of each cell which improves gas exchange) - As cell division contiunes, morula (solid ball of cells) forms - Blastulation occurs when morula develops a cavity called blastocoel -By 4th day, becomes hollow sp