The Cell Flashcards
Name two prokaryotes
Bacteria and archaea
Cell fractionation
Technique for studying cell structure in which cell components are separated using a centrifuge (spins tubes holding mixtures of disrupted cells at various speeds) this results in a fraction of cell components that settle at the bottom forming a pellet with large parts at low speeds + small parts at high speeds
Name 4 eukaryotes
Protists, fungi, animals and plants
The endomembrane system consists of
The nuclear envelope, the endoplasmic reticulum, the Golgi apparatus, lysosomes, vacuoles and the plasma membrane
The endoplasmic reticulum
An extensive network of membranes that consist of membranous tubules and sacs called cisternae. It separates the ER lumen from the cytosol.
Function of smooth ER
Metabolic process e.g synthesis of lipids, metabolism of carbs, detoxification of drugs and poisons.
Function of rough ER
Production of proteins for secretion e.g pancreatic cells synthesize insulin on the rough ER and secrete it into the blood stream
Lysosomes
Membranous sacs containing hydrolytic enzymes that an animal cell uses to digest macromolecules
Name the three types of intercellular junctions in animal cells
Tight junctions, desmosomes and gap junctions
Tight junctions
Plasma membranes pressed together and bound by proteins
Desmosomes
Structures that act like rivets (keratin protein) they fasten cells together in sheets
Gap junctions
Junctions which provide cytoplasmic communication channels
Amphipatic molecules
Have both a hydrophilic and hydrophobic region e.g phospholipids
Light microscope
Visible light is passed through the selectmen and then through glass lenses
Electron microscope
A beam of electrons is focused thought the specimen or on its surface
Features that prokaryotes and eukaryotes have in common
- plasma membrane
- cytosol
- chromosomes
- ribosomes
Proteins made from free ribosomes function
Function within cytosol e.g enzymes that catalyse glycolysis
Function of proteins made from bound ribosomes
Insertion into membranes, for packaging with organelles e.g lysosomes and for secretion from the cell
The central vacuole contains cell aap which can store?
Proteins, ions, metabolic by-products, colour pigments, plant poisons and water
Cellular respiration
A metabolic process that generates ATP by extracting energy from sugars, fats and other fuels with the help of oxygen
Photosynthesis
Converts solar energy to chemical energy by absorbing sunlight and using it to drive the synthesis of organic compounds
Three types of molecular structures of the cytoskeleton
Microtubules, microfilaments, and intermediate filaments
How are plant cell walls formed
Cellulose microfibrils are secreted into the extracellular space where they become embedded in a matrix of other polysaccharides and proteins
Plasmodesmata
Channels that perforate plant cell walls which connect the chemical components of adjacent cells. These connections unify the plant into one living continuum
