Eukaryotes Flashcards
Eukaryotic cells
Made up of protists, fungi, animal and plant cells. They have true nucleus’ as their organelles have membranes
Cytosol
Cytoplasmic solution around organelles used for energy metabolism, and molecular sythesis
Plasma membrane
Formed from a variety of proteins that:
Help things in and out of the cell
Act as receptors
Act as markers so that the immune system knows not to kill them
Plasma membrane receptors
Recognize and bond to other molecules. Sometimes other cells
Cell wall
Forms on the outside of the plasma membrane (extracellular). Is not in animal cells
Nucleus
Separated from the cytoplasm by the nuclear envelope
Lamins
The think protein layer that lines and reenforces the nuclear envelope
Nuclear envelope
A structure that contains both membranes of the nuclear wall and the nuclear pores
Nuclear pore complex
100’s in the nucleus. Made up of nuclioporins
Nucleoporins
Large, octagonal cylindrical structures made from proteins. Exchange components between the nucleus and cytoplasm. Make sure only the good things enter
Nuclear pore
A channel thru the NPC. Allows for assisted exchange of RNA and protiens
Transport protiens
AKA shuttles carry RNA/proteins called the cargo through the nuclear pores
Nuclear localization signal
A short amino acid code that allows a specific protein to bond with it and carry it to the nucleus
Example of nuclear localization signal
An enzyme for replicating and repairing DNA
Nucleoplasm
A liquid/semiliquid in the nucleus
Chromatin
A combination of DNA and proteins. Take up most of the nucleus’ space.
Hereditary information
Distributed along many linear strands of DNA
Eukaryotic chromosome
1 complete DNA molecule and its associated proteins
DNA lengths in the 2 cell types
Eukaryotic is 2-10m, prokaryotic is 1.5m
Nucleoli
One or more in a cell. Form around the genes coding for rRNA.
rRNA to ribosome progression
RNA genes- rRNA molecules (and proteins)- ribosomal subunits- travel to the cytoplasm via the nuclear pore (add mRNA)- ribosome
Ribosome
Large and small subunit. Same function as prokaryotic ribosomes. Bigger and have 4 rRNA molecules and 80+ proteins
Ribosomes can be
Suspended in cytosol, or attach to a membrane
Suspended in the cytosol products location
Proteins may stay in the cytoplasm, go to the nucleus, mitochondria, or cytoskeleton
Nuclear proteins
Part of the chromatin. Line the nuclear envelop or nucleoplasm solution
Proteins made by ribosomes attached to a membrane go…
Most of them attach to an ER allowing them to travel to different organelles
Endo membrane system
Internal, membranous sacs that divide the cell.
Endo membrane system jobs
Synthesis of proteins and lipids, modification of proteins and destroying toxins
Endomembrane system connection
Either physical or by vessicles
Vessicles
Small membrane bound compartments that transfer substances
Endomembrane system includes the
Nuclear envelope, ER, Golgi complexes, lysosomes, vesicles and plasma membrane
Endoplasmic reticulum (ER)
Inter connected network of membranous channels and vesicles (cisternae)
Rough ER
Many ribosomes stud the outside.
Protein made on the rough ER transport path
Travel to the ER lumen- fold into its final form- sometimes chemical modification- transport in vesicles through the cytosol- stop at Golgi complex- chemical modification?-final destination
Cisternae
A single membrane that surrounds the ER lumen
Outer membrane of nuclear envelope
Rough, connected with the rough ER,
Proteins made on nuclear envelope progression
Go between the two layers of the membrane- travel into the ER- final location
Smooth ER
No ribosomes. Produces lipids for cell membrane. Connected to the rough ER
Liver cells smooth ER
Turns toxins such as alcohol into substances that can be digested or removed
ER proportions
That of what the cell is required to make. More protein needed more rough ER. More lipids needed more smooth ER
Golgi complex
S stack of flattened stack called cisternae without ribosomes. 3-8 disks per cell, and are located between the rough ER and the plasma membrane
Protein to chemical modification process
A protein goes the the Golgi complex in a vesicle from the ER, the vesicle bonds with the cis face and deposits the protein for chemical modification
Cis face
Side of the golgi that faces the nucleus
Chemical modifications
Removing amino acids, adding functional groups, adding lipid or carbohydrates
Golgi to final destination progression
The protein travels to the trans side and a vesicle picks it up and brings it to the destination which its modifications say (act as a postage stamp)
Secretory vessicles
Transport proteins to the plasma membrane using exocytosis
Exocytosis
Vesicles fuses with the plasma membrane and dumps its load outside the cell. The vesicle becomes part of the membrane
What do vesicles carry?
Hormones, neurotransmitters, waste, toxins, enzymes
Endocytosis
Brings an outside molecule in. The plasma membrane forms a pocket leading to the endocytic vesicle, the vesicle traves to the Golgi complex for sorting (lysosome in animal cells)
Lysosomes
Small membrane bound vesicles that break down lipids, proteins, carbohydrates, nucleic acids, and polysaccharides. Many different shapes
Central vacuoles are only
In animal and plant cells
How are lysosomes formed?
By budding Golgi. A hydrolytic enzyme is formed in the ER, modified in the ER lumen and vesicles bring it to the lysosome
How burst lysosomes don’t kill the cell
The hydrolytic enzyme only lives in acidic conditions which a lysosome is. The cells cytosol is slightly basic which kills the enzyme
Lysosomal enzymes
Digest several types of food through endocytosis
Endocytosis
When a endocytic vessel fuses with a lysosome
Autophagy
A process of digesting not functional organelles. A large membrane surrounds the dead organelle with a lysosome inside, where the hydrolytic enzyme kills it
Phagocytosis
The process of a cell engulfing a bacteria or debris and destroying it. Executed by hydrolytic enzymes
What cells use phagoctyosis
White blood cells called phagocytes
Lysosomal storage disease
A genetic condition where the hydrolytic enzyme is absent. Substrate of the enzyme build up and interferes with cell function
Tyasachs disease
A failure of the CNS to produce an enzyme to break down fatty acids. Is fatal
Mitochondria
Membrane bound organelles where cellular respiration occurs. Most of our bodies oxygen goes here
Cellular reparation
THe process of breaking down energy rich molecule into H2O and CO2. Mainly ATP is made
Mitochondria are enclosed by
outer mitochondrial membrane and the inner mitochondrial membrane
Outer mitochondrial membrane
Smooth, covers the outside of the oragnelle
Inner mitochondrial membrane
Expanded by folds called cristae
Mitochondrial matrix
Inner part of the mitochondria, ATP creating reactions occur here (and in the cristae), contains DNA and ribosomes similar to bacteria
Cytoskeleton
Gives shape and organization to cells by reinforcing the plasma membrane and structures in the cell, most developed in animal cells
Cytoskeleton apperiance
A system of fibers and tubes that extend into the cytoplasm
Cytoskeleton includes
Microtubules, intermediate filaments, and microfilaments
Plant support
Some cytoskeleton. Mostly the cell wall and central vacuole
Microtubules
The largest and is made from the protein tubulin. Made up of 13 protein fibers
Microtubules measurements
25 nm outer diameter, 15nm inner diameter, 200nm-mm in length
Filament
Linear polymer of tubulin dimer arranged in a head to tail manor creating polarity
Tubulin dimer
Consists of a alpha and beta tubulin bonded non covalently. Create a 1+ and 2- end
1+
Has a alpha tubulin subunits at the end of the microfilament
2-
Has a beta tubulin subunits at the end of the microfilament
Changing length
Tubulin dimers are added of removed from the filament asymmetrically (often more from the 1+ end)
Cell center (centrosome)
Where animal cytoskeleton microtubules radiate from
Centrolies
2 short barrel structures also formed from microtubules
Intermediate filaments
Made from a variety of intermediate filament proteins, extend from the cells center, and are the same shape as microtubules
Intermediate filament example
Karyotin that makes our nail are hair is from cytokeratin
Lamins that line the nuclear envelope
The free end of microtubules anchor to
the ER, golgi complex, lysosomes, secretory vesicles, and the mitochondria
Jobs of microtubules
Provide a track for vesicles to follow, sperate and move chromosomes during cell division, move animal cells, and determine the orientation for growth of an new cell wall
Motor proteins
Push and pull against microtubules and microfilaments to cause animal cells to move
How motor proteins work
One is firmly attached to the cell structure while the other one walks on the microfilament or tubule using ATP
Myosins
Motor proteins that walk on microfilaments
Dynein and kinesins
Motor proteins that walk on microtubules
Intermediate filament size
8-12 nm
Intermediate filaments occur…
Singly, in parallel bundles and interlinked networks. They can be alone, with microtubules, microfilaments, of both. Only in multicellular organisms
Intermediate filaments job
Cell support
Microfilaments
Smallest and are made from 2 polymers of actin subunits wound together
Microfilaments measurements
5-7nm
Actin subunits
Asymmetrical in shape, but are oriented the same way. Polar and have a 1+ and 2- end
1+ end
Growth and disassembly occurs more rapidly
Purpose of microfilaments
Structure and locomotive. 1/2 components that cause muscles to contract. Help divide the cytoplasm in cell division
Cytoplasmic streaming
Active flowing of the cytoplasm allowing for transport of nutrients, proteins, and organelles
Flagella and cilia
Elongated slender, motile structures off the cells surface. A bundle of 9+2 microtubules that arise from the centriole and extend out base to tip
Flagella
Propel the cell with their oar like movements
Cilia
Shorter and are there are more per cell. They move fluid over the cells surface
9 +2
9 double microtubules surround 2 single microtubules
Dynein motor protiens
They slide the 9+2 complex over each other to provide movement
Centriole structure
Similar to the 9+2 except their is no 2 and the 9 is triple instead of double
Formation of flagella and cillia
Centriole moves near the plasma membrane, 2-3 microtubules from each triplet grow, the 2 singles grown without direct connection to the centriole microtubules
Basal body
The centriole the flagellum is connected to
Where are flagella
On protozoa, algae, animal cells (sperm), reproductive plant cells
Where are cilia
Protozoa, algae, cell linings of cavities, ventricles, oviducts, air passages to the lungs (to sweep contaminants out)
Eukaryotic flagellum
Same function, different genes that encode theflagellar apparatus
Types of flagella are
Analogues but not homogenous suggesting that they evolved independently
