Cellular Structures 2.2 U2 Flashcards
What are the important structures in prokaryotes?
DNARibosomesCell Walls Cell MembranePiliFlagella
What is DNA? In prokaryotes
free-floating in cytoplasm, contain genetic information
What are Ribosomes? In prokaryotes
Synthesize proteins
What are Cell Walls? In prokaryotes
Shapes, supports, and protects cell
What is a Cell Membrane? In prokaryotes
Regulates materials entering and leaving cell
What is Pili? In prokaryotes
Short, hair-like structures on cell surface, usually involved in adherence to surfaces
What is Flagella? In prokaryotes
Primarily used for cell movement
What does cocci and bacilli mean?
Cocci - sphericalBacilla - rod shaped
What do diplo, strepto and staphylo mean?
Diplo - = two cellsStrepto - = chain of cellsStaphylo - = cluster of cells
What do Spirillum and spirochete look like?
spirillum is short spaghet and spirochete is long spaghet
What is a gram stain?
A common way to distinguish between types of bacteria, All bacteria (but not archaea!) have peptidoglycan in their cell walls.
What is a gram-negative bacteria?
Gram-negative bacteria have a thin layer of peptidoglycan
What is a gram-positive bacteria?
Gram-positive bacteria have a thick layer of peptidoglycan
What are the main compartments of a eukaryote?
Main compartments = nucleus + cytoplasm
What is the cytoplasm?
semifluid substance, contains everything not in a nucleusMedium for chemical reactions, allows movement through the cell, suspends organelles
What is the nucleus?
Surrounded by nuclear envelope (double-membrane)Nuclear pores in envelope Chromatin is found hereThe Nucleolus
What are nuclear pores?
allow materials to move in and out of nucleus
What is chromatin?
(the spread out form of chromosomes, which are made of DNA)
What is the Nucleolus?
is a small dense region where ribosomes are produced and assembled
What is the endoplasmic reticulum?
Intricate membrane system Has SER and RER
What is SER?
Smooth endoplasmic reticulum (SER) makes and transports lipids, phospholipids, and steroids
What is RER?
Rough endoplasmic reticulum (RER) makes proteins and other membrane parts. Also modifies, sorts, and transports proteins!
What is the ribosome?
Site of protein synthesisMade of rRNA and proteins( and polypeptides)2 subunits: Large(puts amino acids together to form polypeptides) and Small(decode the RNA)Eukaryotes have bigger ribosomes then prokaryotes
What is the Golgi Apparatus?
Processes, sorts, and transports membrane proteins and other secreted proteinsCis face receives, trans face “ships” out(check notes for better explanation)Transport vesicles bud off the trans face to take the protein to the next organelle or to the membrane to be exported
What are Vacuoles?
Stores materials (water, salts, proteins, waste, carbohydrates, etc)Many plant cells have one central vacuole, unlike animal cells
What is the Cytoskeleton?
Network of protein filaments in eukaryotes Helps give shape to cell, provide structure/organization, transport materials along the filaments, and can help the cell moveMicrofilaments and Microtubules
What are Microfilaments?
made of actin(proteins),small, threadlike
What are Microtubules?
made of tubulins(proteins),bigger, hollow, important in cell division
What is Myosin?
Myosin is a motor protein that can “walk” along actin to help move things inside the cell.
What are Vesicles?
Surrounded by membrane, transport materials from one place to another (or out of the cell)Formed by pinching off other organelle (ex. Cell membrane, Golgi apparatus, etc)Fuse with target organelleSome store enzymes that need to be stored at different pH than cytoplasm
What are Lysosomes?
Surrounded by membrane, contain hydrolytic enzymes Break down macromolecules or old organelles into small molecules that the cell can reuse (“recycling”)Common in animal cells, rare in plant cells (central vacuole does this instead)Example:Old protein can be broken down into its individual amino acids, which the cell could then use to make other new proteins!
What is the Mitochondria?
Breaks down food (glucose) to generate useable energy (ATP) for the cellContains its own DNA and ribosomesDouble membrane (inner + outer)Both plants and animals have theseSpace between inner and outer is the inter matrix
What is the Chloroplast?
Captures energy from sunlight and converts it into stored chemical energy (glucose)Contains chlorophyllDouble membrane (inner + outer)Has its own DNA and ribosomesAnimals do NOT have these
What is the Fluid Mosaic Model?
The membrane is a “mosaic” of many different things (phospholipids, proteins, cholesterol, etc) that can move around fluidly within the membrane.
What is the Plasma Membrane?
Thin, flexible barrier around all cellsSelectively permeableRegulates what enters or leaves the cell
What are the Plasma Membrane Components?
Phospholipid, Membrane Protein, Cholesterol, Carbohydrates,
What are the Plasma Membrane Components(Phospholipid)?
Main component of the membraneLipid made of two fatty acid, a phosphate group, and a glycerol moleculeAmphipathicHydrophilic headHydrophobic tail
What are the Plasma Membrane Components(Membrane Protein)?
Membrane ProteinsProteins within the membraneCan be partially within, all the way through, or just loosely attachedMany roles, including signaling, transport, attachment, etc.
What are the Plasma Membrane Components(Cholesterol)?
Lipid made of four fused carbon ringsHelps maintain correct fluidity and stability
What are the Plasma Membrane Components(Carbohydrates)?
Attached to proteins or lipids, on outer surfacePlay role in cell recognition, etc.GlycoproteinsGlycolipids
What is the Cell Wall?
Strong supporting layer around cell membraneMaintains shapeProtects against mechanical stressMost prokaryotes and eukaryotes (ex. plants, fungi) have them, but animals do notPorous, typically allow water, oxygen, carbon dioxide, etc, to pass through
What is Cilia?
Cilia = tiny, hair-like, MANY, many rolesONLY in eukaryotic cells
