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Flashcards by Reece Hill, updated more than 1 year ago
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Created by Reece Hill
about 9 years ago
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| Question | Answer |
| What is Fick's Law? | Rate of diffusion = (Surface area * Diffusion Concentration) / Length of diffusion pathway |
| What are three important facts for the transport method: 'Facilitated Diffusion'? | 1. It is a passive process (uses it’s own KINETIC ENERGY rather than energy derived from Adenine Triphosphate (ATP) 2. Down a concentration gradient 3. Needs a protein carrier or channel |
| Define Co-Transport | When two substances are moved together using a single protein carrier. |
| What do Protein Channels and Carriers do? | Intrinsic proteins that transport specific molecules through the membrane by facilitated diffusion (channels and carriers) or active transport (carriers) |
| What do receptors (relating to proteins) do? | These have a particular shape that only a molecule of complementary shape can bind to. |
| On average, how thin (in nm) are plasma membranes. | 7nm thin. |
| What are three important features of Diffusion? | 1. It is a passive process 2. Net movement of particles, molecules or ions from a high concentration to a low concentration. (down the concentration gradient) |
| How do Phospholipids form a bilayer? | Hydrophilic heads next to cytoplasm inside cell and tissue fluid outside the cell. Hydrophobic tails are not in contact with either aqueous environment. |
| What is the purpose of the phospholipid bilayer? | This prevents passage of water soluble molecules (gluecose) and ions. The tails repel water - soluble substances. However small molecules can still pass through. |
| Phospholipid + Carbohydrate = | Glycolipid |
| What is a phospholipid? | A special type of lipid that contains a phosphate group. |
| What are the main four components the plasma membrane is composed of (in general)? | 1. Phospholipids 2. Proteins 3. Carbohydrate 4. Cholesterol |
| Protein + Carbohydrate = | Glycoprotein |
| What properties does the head and tails have of the phospholipid? | Head is hydophilic (water loving) Tails are hydrophobic (water hating) |
| Where are carbohydrates situated in the phospholipid bilayer? What do they do? | Outer-side of the membrane only - next to the tissue fluid. Involved in cell recognition. |
| What is the secondary structure of a protein about? | Coiling or folding of the chain due to formation of hydrogen bonds. (Involves the Alpha-helix and Beta-pleated-sheet.) |
| What does Cholesterol do in the phospholipid bilayer? | -Small, thin molecule -Fit into the lipid bi-layer giving strength and stability. |
| What is the primary structure of a protein? | The sequence of amino acids in a protein molecule |
| Features of the structure of starch | -Made of alpha glucose -Straight Chain -Tends to coil up |
| What is the plasma membrane often folded into and why? | Microvilli - to increase the available surface area |
| What makes sucrose? | Glucose and Fructose |
| What makes glucose? | 2 alpha glucose isomers. |
| What type of bond join a carbohydrate molecule to a group? | A GLYCOSIDIC bond |
| What are monosaccharides? | Sugars... dissolve in water forming sweet solutions. Monomers for building other carbohydrates. All reducting sugars when heated with Benedicts solution (form a brick red precipitate) |
| What is the test for non reducing sugars? i.e sucrose | 1.Heat a sample with Benedict's reagent. 2.Carry out a second Benedict's test on "hydrolysed sucrose". This is sucrose that has already been boiled for 10 minutes with dilute hydrochloric acid, cooled and then neutralized with sodium hydrogen carbonate |
| What are the three types of macromolecules in living organisms? | 1. Polysaccharides 2. Polypeptides 3. Polynucleotides |
| As the solute increases the water potential becomes more...? | ...negative. |
| What are polysaccharides? | -Many monosaccharides joined together -Many condensation reactions -Glycosidic bonds are formed -NOT sugars as they're insoluble in water |
| What makes lactose? | Glucose and galactose |
| What is the molecular formula of maltose? | C11H22O11 |
| Besides from solute concentration inside the cell, what does water potential depend on? | The pressure exerted on the cell contents by the cell membrane or cell wall (Pressure Potential) |
| What is starch composed of? | Beta glucose 2 types of chain called Amylose and Amylopectin. Amylose(Straight chain) Amylopectin (branched chain). |
| What are the three monosaccharides you need to know? | Galactose Fructose Glucose |
| Lipids are not...? | Polymers (repeated monomers joined together) |
| Describe the test for Starch | Iodine solution. Colour change from yellow to blue-back |
| How are triglycerides formed? | When one molecule of glycerol condenses with three fatty acids. |
| What is cellulose composed of? | Beta glucose. Alternate bonding makes the chains straight Many long, straight, parallel chains crosslinked by glycosidic bonds. |
| What is the structual formula for fatty acids? | R-COOH / R-C==O - OH |
| What are the three polysaccharides you need to know? | Starch Glycogen Cellulose |
| Define R group | A carbon-containing side chain and is different in each type of amino acid |
| Describe the test for a protein | Add NAOH solution and a few drops of CuSO4 solution. A purple colour indicates a protein is present. |
| How many carbons can the R-Group have in its chain? | 16 sixteen |
| What is the quaternary structure of a protein? | The protein consists of more than 1 polypeptide chain - each having its own secondary or tertiary structure. |
| What is the test for lipids? | Dissolve sample in ethanol and pour this into a test tube of water. Cloudy white emulsion indicates a lipid. |
| Wen two amino acids join together in a condensation reaction what is formed? | A dipeptide |
| Many amino acids in a condensation reaction form...? | A polypeptide |
| What stays blue when heated with Benedict's solution? | Sucrose. |
| What is the structural difference between alpha and beta glucose? | In alpha glucose the OH group on carbon 1 is above the plane of the ring. In beta, the OH group on carbon 1 is below the plane. |
| What is the tertiary structure of a protein? | Overall 3D structure of the molecule. Formation of hydrogen bonds, disulphide bridges and hydophobic and hydrophilic interactions. |
| Describe the test for a protein | If a protein is present the solution changes colour from pale blue to lilac. |
| Define water potential | Measure of the free kinetic energy of water in a system. Measured in KPa. |
| What are protein channels? | Have a hydrophilic lining and allow the passage of very small water soluble molecules. |
| What molecules can diffuse through the phospholipid bilayer | Lipid soluble Small and uncharged |
| When is the rate of facilitated diffusion the highest? | Short length of diffusion Large surface area Large concentration difference High temperature Amount of channels |
| What do nuclear pores do? | Control movement of substances between nucleus and cytoplasm. |
| What is the function of a slime capsule? | Provides protection |
| What must happen before the second spin during homogenisation? | The supernatant must be poured off |
| What is the liquid above the pellet called. | The supernatant |
| What is the mixture below the supernatant called? | T |
| Why is tissue homogenised? | To break open the cells to release the organelles |
| Why is the homogenate filtered? | To remove any debris like cells thaat haven't been broken apart |
| W | A solution of sugars, amino acids and sometimes pigments. |
| What does light/dark imagery depend on? | Density. As electrons are absorbed more at denser parts of the specimen |
| What kind of image do TEMs and SEMs give? | TEMs: Flat image SEMs: 3D image |
| What are the advantages of TEMS over SEMS? | Higher resolution can be achieved Higher maginification can be achieved. |
| What is the function of mitochondria? | Produces Adenosine Triphosphate which release energy for active processes. |
| What additional features do Algae and Fungi have? | Algae: Chloroplasts Cell wall Fungi Cell wall |
| What is the resolution of the electron and optical microscope? | Optical resolves objects up to 200nm apart. Electron: Higher as electron beam wavelength is shorter than that of light |
| What is the function of glycogen in animal cells? | Acts as a storage compound |
| What is the function of the cystoplasm in an animal cell | Most chemical reactions occur here |
| Define tissue | A group of similar cells working together to carry out a specific function |
| What does M=? | E/A Enlarged/Actual |
| How do we convert mm into nm? | X1000 |
| What is the magnification of the optical and electron microscope? | Optical: Up to X1500 Electron: over X500'000 |
| What glycoprotein is the cell wall made of in bacteria? | Murein |
| What is the functrion of the Golgi appartus? | It transports and chemically modifies substances. For example combining proteins with carbohydrates to make glycoproteins. |
| What is the function of the smooth endoplasmic reticulum? | Makes and transports lipids |
| What is the solution inside the chloroplast called? | Stroma |
| What is the purpose of a cell surface membrane? | Controls the entry / exit of substances. It is partially permeable to do this |
| What does the nucleolus produce? | Ribosomes |
| What are the limitations of electron microscopes? | large vacuum kills only living specimen The images produces are balck and white Due to harsh preparation artefacts may be produced |
| Describe the structure of a virus | Genetic information A protein coat called a capsid Attatchment proteins |
| Advatnages of SEMs over TEMs | 3D telescopic view Can view surface of the specimen Thin sections do not need to be prepared |
| What is the function of the Rough endoplasmic reticulum? | Transports proteins around the cell. |
| Describe the structure of a virus | A cellular: they do not have cells Non living: they can not reproduce outside the host cell they have entered and have no mode of mode of metabolism respiration. |
| Describe a plasmid | Double stranded, carries extra genetic inforamtion |
| Define organ | A group of different tissures contributing to an overall function |
| Define resolution | The ability to see points close together. It is the degree of detail visible in the image. |
| Describe the structure of Mitochondria | 2 membranes, innerfolded into cristae and a solution called the matrix inside. Also has circular DNA. |
| Define cell theory | The unifying concept in Biology and states that cells are the basic units of structure and function in all living organisms. |
| What additional structures may some proklatryotic cells have? | One or more plasmids Capsule surrounding the cell One or more flagella |
| Define maginification | The number of times the lens makes the image bigger than the object |
| What is indirect evidence for evolution? | All life on Earth exists as cells with basic features in common. Some cells have extra features. |
| What is the plasmodesmota | A gap in the cell wall through which the cystoplasm can pass through adjacent cells |
| What are internal membranes in the chloroplast called? | Thylakoid membranes |
| What is the function of Lysosomes? | Used to digest and destroy unwanted material in a cell. |
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