F211 Cells Keywords and Info


A Levels Biology (F211 - Cells, Exchange and Transport) Flashcards on F211 Cells Keywords and Info, created by Gurdev Manchanda on 05/05/2015.
Gurdev Manchanda
Flashcards by Gurdev Manchanda, updated more than 1 year ago
Gurdev Manchanda
Created by Gurdev Manchanda over 8 years ago

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Question Answer
Cytoskeleton - properties and functions consists of microtubules (hollow protein tubes) and microfilaments (protein strands) 1. transport vesicles & organelles within the cytoplasm around the cell 2. help maintain the cell shape, strengthen 3. can help to move the flagella / undulipodium 4. hold the organelles in position
Prokaryotic organisms/cells single celled organisms made up of prokaryotic cells Naked DNA no nuclear envelope, Circular DNA may have flagellum extremely small have a cell wall- polysaccharide - peptidoglycan small ribosomes
eukaryotic organisms/cells multicellular organisms eukaryotic cells nuclear envelope around DNA no cell wall larger cells larger ribosomes
Microscope equation magnification =
Light Microscope Shines light through specimen low resolution = 0.2 microm low magnification = x1500 object can be stained so you can see better, not white
Transmission Electron Microscope uses electro magnets to focus beam of electrons thru specimen, elctrons are absorbed by specimen, dense areas= absorb more electrons = darker on image highest resolution = 0.0001 microm - look at small organelles highest magnification = x 1000 000 staining may be necessary have to cut very thin slices of specimen have to be skilled
Scanning Electron Microscope Focus a beam of electrons at an angle onto specimen, record bounces of electrons using cathode ray tube
explanation of the bohr effect carbon dioxide diffuses into erythrocytes carbonic anhydrase converts carbon dioxide and water into carbonic acid carbonic acid splits into hydrogencarbonate ions and hydrogen ions
Mass Flow Hypothesis : At the source AT THE SOURCE: 1. active transport move H+ ion from sieve tube element into companion cell 2. facilitated diffusion using carrier protein, moves ion + assimilate (sucrose) back into sieve tubes of the phloem at the source 3. this lowers the water potential in the sieve tubes so water enters the tubes by osmosis
Mass flow hypothesis: At the Sink AT THE SINK: 1. assimilates are removed from phloem to be used up 2. increased water potential in sieve tubes at source 3. water leaves tubes by osmosis, lowering pressure inside sieve tubes at sink.
Osmosis net movement of water from an area of high WATER POTENTIAL to are of low WATER POTENTIAL, via a PARTIALLY PERMEABLE MEMBRANE water potential = tendency for water molecules to diffuse into another area low water potential (-ve no.s kPa) = less 'free' water molecules = solutes present high water potential (0 kPa) = more 'free water molecules = no/fewer solutes present
Mitosis: cell cycle - Interphase INTERPHASE: Gap phase 1 - cell growth and new organelles are made Synthesis - cell replicates DNA Gap phase 2 - cell keeps growing, proteins for cell division are made
Mitosis: cell cycle - Prophase PROPHASE: chromosomes condense nuclear envelope breaks down centrioles move to opposite ends and form spindles
Mitosis: cell cycle - Metaphase METAPHASE: chromosomes line up on spindle equator become attached to spindles by centromere
Mitosis: cell cycle - Anaphase ANAPHASE: centromeres divide, separates each pair of sister chromatids spindles contract pulling chromatids to opposite ends
Mitosis: cell cycle - Telophase TELOPHASE: chromatids uncoil = called chromosomes nuclear envelope forms around DNA CYTOKINESIS: cytoplasm divides, cell surface membrane constrics into two daughter cells
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