Quiz 1: Reading Info Flashcards
Cytoplasm
aqueous internal solution and suspended particles
Cytosol
just aqueous solution
Metabolite
intermediated in biosynthetic and degradation pathways
What limits cellular dimensions?
lower limit of size set by minimum number of biomolecules required by the cell
upper limit of size is set by the rate of diffusion: need a high surface-to-volume ratio for diffusion to occur
Are eukaryotes more closely related to bacteria or archaea?
Archaea
Share closer common ancestor
Types of single cell organisms
Archaea- extreme environments
Bacteria- soils, surface waters, tissues of other organisms
What organelles do all cells have?
cytoplasm, plasma membrane, ribosomes
What types of cells have a nucleoid?
Bacterial cell
Do bacteria cells have membrane bound organelles?
No
Cell envelope
the plasma membrane and the layers outside of it
differ in bacteria cells (gram+, gram-, etc.)
Gram positive bacteria
have a thick layer of peptidoglycan outside their plasma membrane but lack an outer membrane
Gram negative bacteria
have an outer membrane composed of a lipid bilayer
the cell wall is wedged between 2 membranes
What is in the outer membrane of gram negative bacteria?
1) porins: provide transmembrane channels for low molecular weight compounds and ions to diffuse
2) lipopolysacchrides
Do archaea have cell walls?
yes, normally made of peptidoglycan or hard protein
plasmids
small circular segments of DNA in the cytoplasm of bacteria
outside of the main DNA in the nucleoid
What gave the first hints that bacteria and archaea constitute different domains?
ribosomal differences
Size difference between eukaryotic cells and bacteria/archaea cells
5-100µm for eukaryotic cells
2µm for prokaryotic cells (less stuff to contain)
Mitochondria
site of most of the energy extracting reactions of the cell
Golgi complex
postmaster of the cell
processes, packages, and targets proteins to other organelles for export
Rough endoplasmic reticulum
site of much protein synthesis
Smooth endoplasmic reticulum
site of lipid synthesis and drug metabolism
Peroxisomes
oxidize fatty acids (breakdown fatty acids)
Lysosomes
filled with digestive enzymes to degrade unneeded cellular debris
vacuoles
store large quantities of organic acids
*large central vacuole found in plant cells
chloroplasts
sunlight drives the synthesis of ATP in the process of photosynthesis
*found in plant cells
Do plant cells have mitochondria?
Yes
Are plant cells or animal cells larger?
Plant cells
Thylakoids
site of light-driven ATP synthesis
Plasmodesma
provides path between two plant cells
How can you determine the function of the different organelles?
gently rupture the plasma membrane by physical shear
then centifuge the organelles
Cytoskeleton
protein filaments that crisscross the eukaryotic cell, forming an interlocking 3D meshwork
provide structure, shape and organization to the cell
3 types of cytoplasmic filaments
1) actin filaments
2) microtubules
3) intermediate filaments
Are cytoplasmic filaments set in place?
No! They constantly change locations and break down into protein subunits
Controlled by regulatory proteins when to move
Endomembrane system
segregates specific metabolic processes and provides surfaces on which certain enzyme-catalyzed reactions occur
Exocytosis and endocytosis
mechanisms of transport that involve membrane fusion and fission, provide paths between the cytoplasm and surrounding medium
allowing for secretion of substances produced in the cell and uptake of extracellular materials
How big are ribosomes?
20 nm
How big are amino acids?
0.5 nm
How big is the mitochondria?
1000 nm
What makes carbon so crucial to life?
Its ability to make 4 stable single bonds and its bonding versatility
What are the central metabolites?
small organic molecules that are the building blocks of life
these molecules may be polar or charged and are soluble in water: this traps them in the cell
Can polar molecules diffuse across the cell membrane?
Most cannot, unless very small
Metabolomics
the systematic characterization of the metabolome under very specific conditions, such as following the administration of a drug
Macromolecules
polymers with molecular weights above ~5000 that are assembled from relatively simple precursors
Oligomers
shorter polymers
What may macromolecules be assembled into?
Supramolecules such as ribosomes
Proteins
long polymers of amino acids
serve as enzymes, structural elements, signal receptors, or transporters
make up the 2nd largest fraction of the cell after water
Nucleic acids
either DNA or RNA
polymers of nucleotides
store and transmit genetic information
Polysaccharides
polymers of simple sugars such as glucose
energy-rich fuel stores, structure for cell walls, extracellular recognition elements that bind to proteins