BIOL 11000 1st Edition Lecture 14Macromolecules - Plant and animal cells are built o- ut of macromolecules - Our food is mostly macromolecules o Some monomers, sugars, amino acids(free), free fatty acids Cells - What is life?o Bears a complex organization o Responds to external environment o Maintains internal environment (homeostasis) o Carries out metabolism and growth Especially energy metabolism using ATPo Reproduces and maintains heredity o Adapts to environment and evolves Cell Theory - All living things are made of cells - All cells come from preexisting cells o Cells explain continuity features: reproduction, heredity, adaptation, etc.Properties of Cells - Most cells < 1mm- Cell size controlled by 2 factors: o Too small not enough room for molecules – DNA o Too large, must import too much food and export too much waste o Bigger cells need more input These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.Cell Types - Prokaryotic - Eukaryotic o Presence of membrane bound nucleus and internal membrane system defines eukaryotic o Absence defines prokaryotic Prokaryotes - Include 2/3 domains of life o Bacteria o Archea - Take up small end of cell size range ( 1-10 um) - Dominant life form on Earth o Greatest number of cells and mass o Enormous diversity - Grow everywhere - Effects on biosphere- source of most of oxygen we breathe, CO2 N2 fix - Cell structure o No nucleus, but genetic material loosely compartmentalized in a nucleoid o Cytoplasm: fluid that fills the cell o Cytoplasm is a soluble part (cytosol) plus suspended molecules o Remaining space filled with water o Plasma membrane surrounds cell o Outside plasma membrane bacteria generally have a cell wall made of peptidoflycan Carb. polymers linked together by short polypeptides to form a net Archea generally don’t have a cell wall - Prokaryotes have few organelles in cytoplasm and no membrane bound organelles - Prokaryotes do have ribosomeso Site of protein synthesis where dehydration synthesis makes covalent bonds in a specific sequence Eukaryotic Cell - Have membrane-bound nucleus - Nucleus contains DNA o Fungi o Protists o Animals o Plants- Organizing principle – compartmentalization and specialization o Special compartments to perform special functions Organelles, membrane- bound isolates reactions Creates need for transport between compartments o Cell types for different organisms - 3rd kind of specialization o In animals neurons, kidney, liver, etc. o Each cell type has different composition and arrangement of organelles Kidney cells use lots of energy- have more mitochondria Cellular Substructures - Cell is the lowest level or organization that is still living o Individual molecules and organelles are not Nucleus - Approximately center of the cell - Surrounded by nuclear envelope: double membrane connected to each other o Inner and outer membrane are different o Inner has special proteins connected to nuclear lamina- associated with inner nucleus functions o Outer bilayer has ribosomes connected to RER- Envelope has nuclear pores, path for traffic between nucleus and cytoplasm Nuclear Function - Contains important genetic material and protects it for the long term o Stored in somatic cells for alife time o Damaged DNA in these leads to cancer/aging o Effectively perpetual storage in germ like cells - Expression of genetic information starts with transcription o DNA copied into RNA molecule with same sequence o Leaves nucleus via nuclear pores to become expressed o DNA stays behind - Determining which parts of genetic information are being expressed at which time ( regulation) Chromatin - Eukaryotic DNA organized into linear double stranded DNA called chromosomes - Chromatin o Genetic material o Large number of non-covalently attached proteins that protect and regulate DNA o RNA being mae by transcription - Euchromatin- DNA actively being transcribed - Heterochromatin- DNA not being transcribed o Condensed- appears dark in electron microscope o Usually located in periphery, near nuclear envelope Nucleolus - Inside nucleus appears as a dense dot - Site of transcription of RNA components for ribosomes o rRNA - Site where ribosome is assembled - Nuclear Lamina o Mesh of polypeptideso On inner surface of inner membrane Nuclear Matrix - Second mesh of polypeptides Located throughout internal volume of
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