3 Flashcards
(41 cards)
· Cell Theory.
Early: Organisms made of one or more cells, Cell is the fundamental unit of life, Cells come from preexisting cells. Additional: All cells have same basic chemical composition, All cells use energy, All cells contain DNA that is duplicated and passed o
· Why are cells too small to be seen with the naked eye?
Because cells must have abundant surface area to allow the cell to quickly exchange materials with its surroundings.
· List and explain the four features common to all cells.
DNA/RNA, ribosomes, cytoplasm, cell membrane
· What is the difference between the nucleus and a nucleoid?
nucleoid - irregularly shaped region of cytoplasm containing a single, circular DNA molecule. nucleus - membrane bound sac that contains DNA (eukaryotic cell.)
· Study the generalized body plan of a prokaryote – Draw, label and learn the functions of each part.
Split out functions of parts
· List the organelles of Eukaryotic cells
Nucleus, RER, SER, GA, Lysosome, Peroxisome, Mitochondria, chloroplast, central vacuole
· What is endoplasmic reticulum?
An extension of the nuclear envelope that forms a continuous, folded compartment
What is the function of smooth ER?
Membrane network lacking ribsomes, SER makes lipids, detoxifies drugs and poisons.
What is the function of rough ER?
Synthesizes proteins destined for secretion from the cell.
What is a ribosome?
Structure built of RNA and protein where mRNA anchors during protein synthesis. Both free in cytoplasm and bound to rough ER.
Where are the proteins produced by free ribosomes used?
In the cytoplasm
Where are the proteins produced by RER ribosomes used?
In specialized organelles, cell membrane or secreted out of the cell
What is the function of the Golgi apparatus? Pap
- **processes polypeptides and lipids delivered from the ER.
- **adds carbs to proteins and lipids making them glycoproteins and glycolipids.
- **Packages finished products in vesicles that carry them to the plasma membrane or to lysosomes.
What are Lysosomes?
Enzymes in lysosome break down large organic molecules into smaller subunits by hydrolysis releasing them into cytoplasm for the cell to use. Breaks down and recycles cellular debris and captured pathogens.
What is the function of Peroxisomes?
Originate in ER and contain enzymes that break down toxic substances like hydrogen peroxide and fatty acids. Produce cholesterol and othe lipids.
· Describe the structure and function of Mitochondria.
Contains two membranes forming inner (cristae) and outer compartments and a fluid interior (matrix) that contains its own DNA and ribsomes. Function - Makes the energy molecule ATP through aerobic respiration.
Name two important functions of the nucleus in a eukaryotic cell.
Keeps DNA away from potentially damaging reactions in the cytoplasm. Nuclear envelope controls when DNA is accessed and controls the passage of certain molecules across its membrane.
What are the components of the nucleus?
Nuclear envelope, Nucleoplasm, Nucleolus
Nuclear envelope?
2 lipid bilayers pressed together as a single membrane surrounding the nucleus. Outer bilayer continuous with ER. Has nuclear pores to allow certain substances to pass thru membrane.
Nucleoplasm?
Viscous fluid inside nuclear envelope
Nucleolus?
Dense region in the nucleous where subunits of ribosomes are assembled from proteins and RNA
Chromatin?
All DNA and its associated proteins in the nucleus.
Chromosome?
Single DNA molecule with its attached proteins. Visible during cell division. Humans 46.
· What is an endomembrane system?
A series of interacting organelles between the nucleus and the plasma membrane.
