Exam 2: Lectures 7-11 Flashcards
Prokaryotes
Small cells with no true nucleus; make up the Domains Archaea and Bacteria
Eukaryotes
Large cells with a true nucleus, an extensive internal membrane, and a diverse and dynamic cytoskeleton; make up the Domain Eukarya
How do prokaryotes and eukaryotes differ?
Prokaryotes are smaller with no organelles, whereas eukaryotes are 1000x larger with organelles to accommodate for their size
Prokaryotes have flagella and fimbria, while eukaryotes don’t
What’s the purpose of organelles?
In eukaryotes, organelles are necessary for the compartmentalization of specific processes. Because the cells are so large, substances cannot move quickly enough across the whole cell. As such, all materials needed for specific processes are contained inside specialized organelles
Name the organelles
- nucleus
- ribosomes
- rough endoplasmic reticulum
- smooth endoplasmic reticulum
- Golgi apparatus
- peroxisomes
- lysosomes
- mitochondria
- chloroplasts (plants)
- plasma membrane
- cell wall (plants, fungi, algae)
- cytoskeleton
Organelle definition
Membrane-bound compartments in the cytoplasm that contain enzymes and other molecules for a specific function
Nucleus
A large, highly organized organelle enclosed by a double membrane (nuclear envelope) with openings (nuclear pores)
Contains the nuclear laminae and the nucleolus; holds genetic information and assembles ribosome subunits
Ribosomes
Not an organelle
Composed of two large and small subunits; made of RNA and proteins and translates RNA and DNA
Rough Endoplasmic Reticulum (RER)
A network of membrane-bound sacs and tubules that extends into the cytoplasm and is continuous with the nuclear envelope; has ribosomes attached which help to perform protein manufacturing
The proteins go inside the RER (lumen), undergo folding, and are released to other parts of the cell
Smooth Endoplasmic Reticulum (SER)
A network of membrane-bound sacs and tubules lacking ribosomes; acts as a lipid processing center and stores internal calcium
Golgi Apparatus
Cisternae (membrane sacs) stacked on top of each other; processes and packages proteins produced in the RER into vesicles for transport to other parts of the cell
Peroxisomes
Globular structures that bud off of the endoplasmic reticulum and perform oxidation reactions that produce hydrogen peroxide; perform the breakdown of fatty acids
Lysosomes
The “trash cans of the cell”; contain acidic interiors with many different enzymes that break down macromolecules into monomers that are able to be used as building blocks in the rest of the cell
Mitochondria
A series of sacs (cristae) surrounded by an outer membrane; contains the mitochondrial matrix
Has its own chromosome (mtDNA) in the mitochondrial matrix; affects growth, development, and production of ATP
Chloroplast
In plants; flattened membrane-bound vesicles (thylakoids) bound in a double membrane and performs photosynthesis
Grana: stacks of thylakoids
Stroma: space around grana
Plasma membrane
Selectively permeable lipid bilayer with proteins that separates the internal and external environments
Cell wall
In fungi, plants, and algae; cellulose fibers in a stiff matrix made of polysaccharides and proteins; provide protection and support
Cytoskeleton
Actin
Intermediate filaments
Microtubules
Nuclear transport
Nuclear pore complex
Which substances pass through the nuclear pore complex and how?
