Things to review for exam 2 The black type is what she said in class to review for the test The blue type is what I found in the book in reference to the topics Good luck you guys Figures that she put on the board Difference between osmosis and diffusion o Osmosis Movement of water across a selectively permeable membrane in response to gradients of concentration pressure or temp Can occur through a phospholipid bilayer OR through aquaporin channels o Diffusion diffusing directly across the phospholipid Simple diffusion bilayer down their concentration gradients concentration gradient with the aid of transport proteins moving through cell membranes down a Facilitated diffusion Fluid mosaic model o Singer and Nicolson developed it o Each membrane consists of a mosaic or patchwork of different proteins that constantly shift and flow within a viscous thick sticky fluid formed by a double layer of phospholipids Plasma membrane lots of questions on this and from this chapter o A bilayer of phospholipids interspersed with cholesterol molecules that form a fluid matrix in which various proteins are embedded Phospholipids o What they are and how they re arranged Hydrogen bonds form between water and the hydrophilic phospholipid heads causing them to be on the outside and the tails on the inside o Structure Tail hydrophobic Head hydrophilic o Phospholipid bilayer tails face each other o Phospholipids with kinked tails More fluid Unsaturated fats Found in cold climates o Phospholipids with straight tails Less fluid Found in warm climates Saturated fats Solution solute gradient fluid o Gradient a physical difference in properties such as temperature pressure electrical charge or concentration of a particular substance in a fluid between two adjoining regions of space o Solution o Solute a substance that can be dissolved into a solvent Water is the universal solvent o Fluid any substance whose molecules can flow past one another as a result fluids have no defined shape this includes fluids gases liquids and cell membranes who s molecules can flow past each other Isotonic equal amount of fluid and solute Solution with a membrane that divides the two solutions they re isotonic o How they re moving is equal to each other STILL MOVING Solute concentration on osmosis o Isotonic solution equal concentrations of solute and water Cells retain their normal shape Equal amounts of water is flowing in and out of the cell contains a greater concentration of solute o Hypertonic solution Cell will shrink crenate More water is moving out of the cell than is moving in o Hypotonic solution more dilute low solution Cell will swell More water is moving into the cell than is moving out o This is where the red blood cell diagram is used as an example it just illustrates the above of cells showing the different shapes o Two different solutions with of concentrations is it hypotonic hypertonic guessing this means that if she says there is a higher concentration on the outside of the cell it is hypertonic and if there is a higher of concentration inside the cell it is hypotonic and if the of concentration is then it is isotonic o Have two important characteristics Self renewal Ability to differentiate into a variety of cell types o When a stem cell divides one of its daughters remains a stem cell maintaining the population of stem cells Stem Cells Mitosis and meiosis o Mitosis cytokinesis a nuclear division followed by cytoplasmic division Gives each daughter nucleus one copy of the parent cell s replicated chromosomes and cytokinesis usually places one of these nuclei into each daughter cell Typically produces tow daughter cells that are genetically identical to each other and to the parent cell and usually contain about equal amounts of cytoplasm Takes place in all types of eukaryotic organisms Asexual reproduction o Meiosis The prerequisite for sexual reproduction Occurs only in ovaries and testes 2 rounds of cytokinesis to produce four daughter cells that can Sexual and Asexual reproduction become gametes eggs sperm o Sexual reproduction gametes sperm and egg from two adults when offspring are produced by the fusion of Meiotic cell division happens in adult s reproductive system to produce daughter cells with exactly half of the genetic information of their parent cells Genetic difference makes these organisms unique produces offspring that are genetically o Asexual reproduction identical to the parent Kind of like cloning Determine male and female XY XX o Men determine gender How many chromosomes does the human have How many chromosomes does the sex cell have o 23 o 2 Haploid and Diploid o Haploid cells that contain only one of each type of chromosome o Diploid cells with pairs of homologous chromosomes Means half Means double DNA molecule know how to transcribe o Made up of four different bases Adenine Thymine Guanine Cytosine RNA know how to transcribe o Same thing except we replace Thymine with Uracil differences between RNA and DNA Strands Sugar Types of bases Base pairs DNA 2 Deoxyribose A T C G A T T A C G G C RNA 1 Ribose A U C G RNA DNA RNA RNA A T A U U A U A C G C G G C G C function Contains genes the sequence of bases in most genes determines the amino acid sequence of a protein messenger RNA mRNA carries the code for a protein coding gene from DNA to ribosomes ribosomal RNA rRNA combines with proteins to form ribosomes the structures that link amino acids to form a protein transfer RNA tRNA carries amino acids to the ribosomes Karyotype cell Centromere o When we view an entire set of stained chromosomes from a single o Specialized region of the chromosome o Two principal functions Temporarily holds two daughter DNA double helices together after DNA replication It is the attachment site for microtubules that move the chromosomes during the cell division Telomere o Repeated nucleotide sequences o end in Greek o essential to chromosome stability o Cell cycle then divide again Nucleotides o The repeating pattern of divide grow and possibly differentiate o Small subunits that make up the long chain of a single molecule of DNA o Each nucleotide consists of A phosphate A sugar deoxyribose One of the four bases A T C or G o DNA in a choromosome consists of two long strands of nucleotides wound around each other like a twisted ladder double helix What did Mendel do o The pea experiment Crossbread plants that differed in two traits Ex seed color yellow or green and seed shape smooth or wrinkled He learned
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