BIOLOGY

• Biology -.txt
• #tags column:12
• What is a cell? "A cell - smallest structural & functional unit of an organism.Every organism is made up of at least one cell"
• What are eukaryotic cells? "Eukaryotic cells - cells that contain membrane-bound organelles (mitochondria, true nucleus, chloroplasts)"
• Draw out a diagram of a typical plant cell. ""
• Draw out a diagram of a typical animal cell. " "
• Define the term cell ultrastructure. "Ultrastructure - structure of a cell in fine detailWe know it thanks to electron microscopesUltrastructure images are usually from TEM"
• Outline the structure and function of the nucleus. "Nucleus - functionContains the DNA of the cell - directs protein synthesis of all proteins required by the cell - controls metabolic activity of the cell (many of the proteins are enzymes necessary for metabolism to take place)Nucleus - structureDNA is surrounded by a double membrane - nuclear envelope - encloses and protects th...
• Outline the structure and function of SER & RER. "Endoplasmic reticulum - network of membranes throughout the cytoplasm enclosing flattened sacs - cisternae.Connected to the outer membrane of the nucleusSmooth endoplasmic reticulumResponsible for lipid and carbohydrate synthesis and storage<span style=""background-color: rgb(204, 255, ...
• Outline the structure and function of the Golgi apparatus. "Golgi body/apparatus - stack of membrane bound cavities (cisternae)Modifies proteins and packages them into vesicles for transport (modifying could involve changing/rearranging the protein strcuture or attaching diff. molecules to protein)Does NOT contain ribosomes"
• Outline the structure and function of ribosomes. "Ribosomes - the site of protein synthesisCan be free floating in the cytoplasm or attached to endoplasmic reticulum forming RER (eukaryotic ribosomes)Can also be in mitochondria, chloroplasts and prokaryotic cells (prokaryotic ribosomes)Not surrounded by a membraneConstructed of RNA made in the nucleolus<img src=""paste-18ca38...
• Outline the function and structure of mitochondria. "Mitochondria - site of aerobic respiration, generate ATPSurrounded by an envelopeInner membrane is folded to form structures - cristaeLiquid inside of inner membrane - matrixHave their 'own' DNA (mitochondrial DNA) and their own 70S ribosomes"
• Outline the general structure and function of vesicles. "Vesicle - membrane bound containers with fluid inside found within cells. (generic term)Involved in internal transport of substances within the cells Can also fuse with cell surface membrane to release its contents (excrete)"
• Outline the structure and function of lysosomes. "Lysosomes - types of vesicles that contain digestive (hydrolytic) enzymesResponsible for breaking down food/waste material in cells (incl old organelles) by fusing with a food vacuole or a vesicle containing old organellesResponsible for breaking down pathogens ingested by phagocytic cellsImportant role in programmed cell death<img src=""paste-a9fd1cdfa...
• Outline the structure and function of vacuoles. "Vacuoles - larger vesiclesMembrane bound (selectively permeable membrane around a permanent vacuole in a plant cell - tonoplast), carry a substancePermanent vacuoles (in plants - very large) - contain cell sapFood vacuoles - temporary - form from plasma membrane, engulf food and lysosome fuses with it to give it enzymes to digest the food<img src=""paste-a9fd1cdfad0ccec7c7f9dc68d1e3d5fe6b...
• Outline the structure and function of chloroplasts. "Chloroplasts - the site of photosynthesisSurrounded by an envelopeWithin the envelope - internal network of membranes which form flattened sacs - thylakoidsStacked thylakoids - granum (contain chlorophyll pigments) which are joined together by lamellaeInternal liquid - stromaHave their own ribosomes (70S...
• Outline the structure and function of the plasma membrane. "Plasma membrane (cell surface membrane)Overall structure: phospholipid bilayer with various proteins and cholesterolControls the entry and exit of substances into and out of the cell"
• Outline the structure and function of a plant cell wall. "Plant cell wall - made of fibrils of cellulose embedded in a matrix of other moleculesProtects the cell from pathogens, gives the cell its shapeHigh tensile strength allows plant cells to become turgid and press against the cell wall, making the cell rigid which supports both the cell and the plant as a wholeFreely permeble - gaps for important molecules to ge...
• Outline the structure and function of the cytoskeleton. "Cytoskeleton - network of protein fibers throughout the cytoplasmSupport the shape and position of the cell and the organelles within (provide mechanical strength to cells)Allow cells to move and the movement of structures within the cell"
• Outline the structure and function of centrioles. "Centrioles - component of cytoskeleton in most eukaryotic cellsComposed of microtubules (9 sets of 3 microtubules)Found at the base of cilia and flagella, thought to play a role in the positioning of themTwo associated centrioles form a centrosome which is involved in assembly and organisation of spindle fibers during cell div...
• State three similarities and differences between a typical plant and animal cell. "
• SimilaritiesDifferences
• Both are eukaryotic (have a true nucleus and membrane bound organelles)Animal cells do not have chloroplasts, plant cells doBoth have a plasma membraneAnimal cells do not have permanent vacuoles, plant cells do<td style=""width:50%; padding:2p...
• Draw and label a diagram of a mitochondrion. ""
• Draw and label a diagram of a chloroplast. ""
• "" ""
• Describe the interrelationship between the organelles involved in the production and secretion of proteins. "Protein synthesis:1. Proteins are synthesised on the ribosomes bound to the endoplasmic reticulum.2. Proteins pass into the cisternae of RER and are packaged into transport vesicles.3. Transport vesicles containing the proteins move towards the Golgi apparatus via the transport function of the cytoskeleton....
• Define the term 'prokaryotic cell'. "Prokaryotic cells - cells (unciellular organisms) that do not contain membrane-bound organelles."
• List examples of eukaryotic and prokaryotic cells. "
• EukaryoticProkaryotic
• ErythrocyteE. coliLeucocyteStreptococcus bacteriumOocyteHepatocy...
• Draw and label a diagram of a prokaryotic cell. ""
• Outline the structure and function of a prokaryotic cell wall. "Cell wallFound below the slime capsuleMade out of peptidoglycan (murein)Provides protection and support"
• Outline the structure and function of the slime capsule. "Slime capsuleOuter layer of a prokaryoteProvides protection from harmful things in the environment, helps bacteria be sticky (adhesive)Polysaccharide coating"
• Outline the structure and function of a prokaryotic plasma membrane. "Plasma membrane Same as an eukaryotic plasma membrane"
• Outline the structure and function of a prokaryotic flagellum. "Flagellum Thinner than the equivalent of eukaryotes, no 9+2 arrangementIt is attached to the cell membrane by a basal body and rotated by a molecular motorMolecular motor causes hook to rotate, creating true propeller motion"
• Outline the structure and function of the bacterial chromosome. "Bacterial chromosomeLocated in the cytoplasm, not in a membraneActs as the 'control center' of the cell - controls metabolic activityIt is a single chromosome which is circularDNA is 'naked' - not wrapped around proteins"
• Outline the structure and function of the plasmid. "Plasmid - small circular loops of DNA in addition to the chromosomeBacteria swap them with each other - form of sexual reproduction, transferring genes"
• Outline the structure and function of pili. "Pili - hair like appendages found on surface of many bacteria/archaeaUsed for swapping plasmids and help them stick to cells and infect"
• Outline the structure and function of prokaryotic ribosomes. "Ribosomes - site of protein synthesis70S in prokaryotes (smaller than eukaryotic)Found in chloroplasts and mitochondria"