Section 5.3 (Exam 1) Flashcards
Eukaryotic Cells Contain Organelles
What organelles are different between plant and animal cells?
Plants have chloroplasts, cell walls, and a larger single vacuole. Both cells have mitochondria.
What are ribosomes? Are they organelles?
Sites of protein synthesis. They are not organelles.
What are the two subunits of ribosomes?
Ribosomal RNA (rRNA) and 50 different protein molecules.
What is the nucleus?
The largest organelle that contains the DNA of the cell.
What is the nucleus made up of and what are its responsiblities?
Double membrane nuclear envelope that contains pores and is continuous with the ER. It contains a concentrated area of ribosomes called the nucleolus and the nucleus is also the site of DNA replication and transcription.
What are chromosomes made up of?
Long thin strands of DNA combined with protein called chromatin.
What is the endomembrane system?
Interconnected system of membrane-enclosed compartments. Includes the cell membrane, nuclear envelope, ER, Golgi Apparatus, and Lysosomes.
Tiny membranous ____________ shuttle substances between the compartments of the endomembrane system.
vesicles
Endoplasmic reticulum (ER)
Network of membranes in the cytoplasm with a large surface area. Consists of Rough ER and Smooth ER.
What is the Rough ER (RER)?
Ribosomes are attached to this extended membrane, making it seem rough.
What is the lumen?
Space within a membrane-bound organelle or structure.
What is the Smooth ER (SER)?
It has no ribosomes and is continuous with the RER.
What are the roles of the SER?
Chemically modifying small molecules like drugs and pesticides so they can be easily removed, site of glycogen degradation to release glucose, synthesizes lipids and steroids, and stores calcium ions.
What are the roles of the RER?
New proteins enter the RER’s lumen and are modified, folded, and transported to other regions via vesicles.
What is the Golgi Apparatus made of?
Flattened sacs (cisternae) and small vesicles.
What are the roles of the Golgi apparatus?
Receive proteins from the RER; modify, concentrate, package, and sort proteins; synthesize polysaccharides for cell walls in plants; cutting precursor proteins into functional fragments