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BIOL 1000
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Bio 1000 September 7, 2012 Pigment absorbs light Photoreceptor a light sensor made of protein and associated pigment, light hits pigment and makes conformational change in pigment which makes a change in protein (signal transduction cascade) Negative phototaxis- move away from light stimulus Compound eye- hexagons (ommatidium) Third diagram Light passes through cornea and back lens the retina Blind spot on the retina, allows optic nerve to be sent through retina to the brain September 10, 2012 Circadian rhythm- you use light to set your biological clock, not necessarily if its dark you sleep. Also, its controlled by an internal (endogenous) organism-based clock How do circadian rhythms work? Melatonin production may be low in some people Blind animals still have photoreceptors so they’re able to set a biological clock Coevolution- adaptations make 2 or more populations evolve, and they interact with each other Is there a dark side of light? Light can damage biological molecules (including dna) How can we be protected from sun damage? Melanin absorbs uv rays Vitamin D3 (cholecalciferol)- made in skin Some vertebrates (organisms with a backbone) don’t see the sun - Light is the visible region of the electromagnetic spectrum - It is a source of energy and information - It plays a role in the behaviour and ecology of all organisms (circadian rhythms) - It can also damage biological molecules (UV radiation) September 12, 2012- biodiversity of life Species- a group of organisms that are capable of interbreeding and producing fertile offspring of both genders, dna similarity, habitat Heterotrophs: obtain organic carbon and energy by consuming other organisms Autotrophs: synthesize organic carbon molecules using inorganic carbon, CO2 Photoautotrophs: Use light as source of energy for photosynthesis Chemoautotrophs: use reduced chemicals rich in electrons as an energy source Archaea and bacteria produce through binary fission Eukarya goes through sexual reproduction Similiarities between archaea, bacteria and eukarya: dna, cell membrane, translation and transcription machinery and have a way to get energy Selection-how does it relate to biodiversity? - When some force or phenomenon affects the survival and reproduction of individual organisms - Selection directed by different circumstances September 14, 2012 Community- 2 or more populations living in the same area Evolution- A change in inherited traits/characteristics over time Population- group of individuals from same species that live in same area and regularly interbreed Evolution is valid science Theory of evolution- explains the unity and diversity of life - Highly fertile - Food resources - Genetic variation Evolution of life on our planet may have been an inevitable outcome of initial physical and chemical conditions established by Earth’s origins Anoxygenic- photosynthesis not producing oxygen, influenced by sulphur Oxygenic- photosynthesis bacteria appears oxygen produced, influenced by oxygen Bacteria could go under evolution as well (horizontal gene transfer) Hydrogen bonds hold A-T and C-G together Adenine and Thyamine have a weaker bond Linked by phosphor diesther bond September 17, 2012 Once protein starts translating with (n terminal) when its done translating we end up at the c terminal (carboxyl) Primary- amino acids in a sequence Secondary- linking between primary amino acids Tertiary- folding in amino acids Quaternary- structure of protein starts forming Redox reactions are important with metabolism Most energy is released from ATP by removing last phosphate group September 19, 2012 ORI stands for origin of replication, it starts the replication Marker- allows plasmid to grow if it has the gene MCS- has about 20 restriction sites A restriction site allows the enzyme to recognize where it can cut on the plasmid Final product is what we call recombinant DNA Putting the recombinant DNA into a bacterial cell is called transformation Bacteria competence- bacteria able to take up plasmid Ligation joining pieces of DNA, enzyme called DNA ligase Plasmid could close on its own Liquid needs to contain AMP (amphisiilan) Bacteria responds to the presence of amphisilan Selection helps determine which bacteria is growing and which contains the insert September 21, 2012 Organelle- has to have a membrane around them, have a specialized function, only be found in a eukaryote, they’re suspended within the cell cytosol Cytosol is the liquid portion of the cell Cytoplasm is liquid plus organelles Endomembrane system- vesicle allows things to fuse with organelles Nucleus is where rRna is transcribed and small and large ribosomes subunits are made Nuclear Pore- things can enter and leave Nuclear Lamina- structural support mRNA needs to get out of the nucleus Enzymes need to get in and out of the nucleus as well as ATP and ions Nucleotides, hormones, rRna, ribosomes are things that need to get in/out of the nucleus Importance of the nuclear membrane- we keep it separated because we don’t want to damage the DNA Archaea associate with histone like proteins 4 of them Image of histones- there are 8 histones, the 4 are doubled, the black is the DNA and once its wrapped around its called nucleosomes, octomer consists of H2A, H2B, H3, H4 Heterochromatin- tightly packed, you don’t want being new stuff being transcribed while it is being replicated, mostly 30nm Euchromatin- loosely packed, 10nm is more spread out September 24, 2012 Chapter 1-3, 21 and biotechnology for bio test and check moodle- NEXT WEEK Rough Endoplasmic Reticulum is covered in ribosomes (little dots) Smooth endoplasmic reticulum- plays a role in lipid synthesis, regulates calcium, carbohydrates, breaks down some drugs Vesicle- brings stuff from one organelle to another organelle Golgi apparatus- after leaving the ER, it moves to the Golgi, in the Golgi a sugar group is added to the protein which is called glycosylation (the sugar is added after the protein is translated) Lysosomes- have a very acidic environment; their pH level is around 4.8 Macrophage contains lysosomes Organelles come from pre-existing organelles Endomembrane system doesn’t include mitochondria and chloroplasts September 26, 2012 Dyneins - we find them in animal cells, some in plant cells it is used to transport vesicles and organelles - Known for flaggeral movement in Eukaryotes - There has to be a motor protein for movement - Dynein moves along microtubules, which allows bacteria’s flagellum to move in a whip like motion Cilia moves stuff, they are hair like structures and they can be found in the trachea (helps you sneeze) Flagella of prokaryotes and eukaryotes ARE NOT EVOLUTIONARILY RELATED Myosin moves along the actin to generate enough power which produces a muscle contraction Myosin also plays a role in cell division Mutation in kinesin (motor protein) will allow organism to not function properly Extracellular matrix is located outside the cell membrane, it is used to specialize the cell (ex. Bone, cartilage, skin, cardiac muscle, intestinal villi, skeletal muscle) ECM- helps to provide structural support and helps to provide its function (don’t confuse with mitochondrial matrix) Eukaryotic cells are bigger than prokaryotic cells because they have a bigger endomembrane, volume will increase but by having the endomembrane system the surface area will support the volume (works lik
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