Unit Two: Overall Cell Knowledge Flashcards
What are the 2 Types of Cells
- Prokaryotes
- Eukaryotes
What are Prokaryote Cells
- smaller than eukaryotic cells
- microns in length
- 3 major shapes: spherical, rod-like, sprial
Prokaryotes: Nucleoid
- region of the cell within highly folded mass of DNA
- single circular molecule that unfolds when released
- containing genes
- instructions for making new proteins
- composed with DNA, mRNA, ribosomes, rRNA
Prokaryotes: Cell Wall
- cell wall does not = cell membrane
- glucocalyx covering (polysacch) slime layer
- provides protection
- attatches to surface of other prokaryotes
- forms a colony
Prokaryotes: Cytoskeletal Structure
- filamentous content
- maintains shape/structure
- guides cell division
- composed of flagella and pili
Prokaryotes: Flagella
- extension of the cell
- propels prokaryote through fluid environment
Prokaryotes: Pili
- hair like shafts extending from cell wall function
- attach prokaryote to surfaces of other cells
What are Eukaryotic Cells
- reffered to as a domain: eukarya
- 4 main groups: fungi, protists, plants, animals
Eukaryotes: Plasma Membrane
- plants, fungal, and protist cells extracellular wall
Eukaryotes: Nucleus
- surrounded by nuclear envelope
- embedded with nuclear pore complexes (nucleoporins)
- proteins and RNA molecules
- space inside nucleus filled with chromatin
What are nucleoproteins
- exchange molecules between the nucleus and cytoplasm
- protein selective
Eukaryotes: Chromatin
- any collection of eukaryotic DNA molecules
Eukaryotes: Nucleoli (one or more)
- bodies within the nucleus
- forms around genes
- form ribosomal units until exported
What is the Cytoplasm
jelly-like material holding organelles in place
What are Vacuoles and Vesicles
storage and transport abilities inside cells
What are Lysosomes
- digestive purposes
- absorbs, breaks up, and neutralizes toxins
What is the Mitochondria
- ATP production with O2
- “powerhouse” of cell
What is the Nucleus
- protects DNA material
- controlls cell activities
What are the Ribosomes
builds and composes proteins
What is the Endoplasmic Reticulum (ER)
- works on protein synthesis
- membrane production
What is the Cell Membrane
- cell boundry
- controls movement in and out of cell
- recognizes signals
What is the Plasma Membrane
- encloses the cell, defines boundaries
- transmits information from outside to inside
- maintains life supporting differences between cytosol and extracellular environment
What are the Components of the Plasma Membrane
- Phospholipids (fundamental unit)
- Proteins
- Glycoproteins
- Cholesterol (20%)
What is the Phospholipid Bilayer
- 2 layers of lipid molecules
- approx 5 nm thick
- impermable to most water soluble molecules
What are Membrane Proteins
- Serves as receptors detecting extracellular molecules
- Molecule transport between cytosol and extracellular environment
- Catalzying membrane bound reactions (ATP)
- Structural links with cytoskeleton
30% of animal genome codes for membrane proteins
What are Ribosomes
- large and small subunits
- 4 types of RNA molecules and over 80 proteins
- found within the cytosol
- protein synthesis cordination
- “workbench”
- often called a **ribozyme **
What is the Function of Ribosomes
transfer the “code” from mRNA into assembly of amino acids making a protein
What is the Endomembrane System
- endo: “within”
- 2 types: rough and smooth
What is the Function of the Endomembrane System
- synthesize and transport new proteins
- sythesis of lipids
- detoxfication
What does the composition of a Ribosome look like
- no membrane
- over 50 different proteins (ribosomal proteins)
- ribosomal proteins make up 1/3 of the ribosomes
- RNA molecules translates and executes messages to DNA
- Ribosomal RNA make up 2/3 of ribosome
How many Ribosomes exist within a cell?
10^6
What are the two forms of Ribosomes
- Free
- Bound/Fixed (membrane bound)
What are the two main components of a Ribosome
- Small: correctly matches tRNA to mRNA codes
- Large: catalyzes peptide bonds, makes polypeptides
1 peptide/s (eukaryotes) —–> 20 peptide/s (prokaryotes)
How much of the cell volume does the nuclue occupy?
- occupies 10% of cell volume
What does the Nucleus do
one thing
- make new protein
- houses “blueprint” for construction
Major Functions of the Nucleus
- Amino Acids on “hand” amino acid pool
- Tear down existing structures (protein breakdown)
- Diet Function
What is the Nuclear Envelope
2 lipid bilayers
Describe the Nnucleau Envelope
- proteins manufactured by ribosomes transported in space
- keeps cytsol and nuclear enzymes apart
- directly connected to the ER
- ribosomes on surface
- punctured by nuclear pores
- transport of molecules into and out of nucleus
What are some Key Features of the Nuclear Envelope
- nuclear envelope (inner and outer membranes, intermembrane space)
- nuclear pore complex
- nucleoplasm
What are some important Nuclear Proteins
- Histones
- DNA and RNA polymerase
- Gene regulatory proteins
- RNA processing proteins
