A Level Biology - (Up to proteins)

Reece Hill
Flashcards by , created about 3 years ago

Hello, I have made this resource in preparation for my Biology assessment, however please feel free to make sense of it and acquire the information to your own knowledge.

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Reece Hill
Created by Reece Hill about 3 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.