Ch.3 Parts of a Cell Flashcards
This is the cell forming material between the plasma membrane and nucleus.
Cytoplasm
This is viscous fluid with properties of colloid and solution that suspends organelles.
Cytosol
This is the metabolic machinery of a cell, includes ribosomes, endoplasmic reticulum, golgi apparatus, lysosomes and cytoskeleton.
Cytoplasmic organelles
Chemical substances like stored nutrients ( glycogen and lipid droplets), pigments (melanin), and crystals (crystalline waste products).
Inclusions
This it the sausage shaped powerhouse of the cell. It makes most of the ATP for the cell. It has its own DNA and RNA but still needs nuclear DNA for most proteins.
Mitochondria
What are the two membranes of the mitochondria?
- Smooth outer membrane
2. Inner folded to form Cristae
Where does ATP synthesis occur within the mitochondria?
Cristae (inner folded membrane)
This is the factory of the cell. It is comprised of ribosomal RNA and makes the proteins for the cell. It is free floating or attached to rough endoplasmic reticulum.
Ribosomes
Free floating ribosomes make protein for?
Cytoplasm
Membrane bound ribosomes make proteins that?
Make proteins that can be exported to ECF or plasma membrane.
This is an extensive system of interconnected tubes and parallel membranes enclosing fluid filled cavities called cisterns. It also accounts for half of the cell membrane.
Endoplasmic Reticulum
What are the two types of Endoplasmic Reticulum (ER)?
- Rough ER
2. Smooth ER
This is studded with ribosomes and is a protein and membrane factory.
Rough ER
These enzymes catalyze reactions involved in the following tasks:
- Metabolizing lipids
- synthesize steroid based hormones such as sex hormones.
- Absorbs, synthesize, and transport fats.
- Detoxify drugs, certain pesticides, and cancer causing chemicals.
- Break down stored glycogen to form free glucose.
Smooth ER
This consists of stacked and flattened membranous sacs shaped like hollow dinner plates. It is the “traffic director” for cellular proteins.
Golgi Apparatus
What is the major function of the Golgi Apparatus?
To modify, concentrate, and package proteins and lipids made at the rough ER and destined for export from the cell.
Golgi apparatus are sometimes called ____ because they are dark and packed.
granules
Transport vesicles from the ER fuse to ___ face of golgi and shipped on ___ face.
Cis
Trans
What is Cis face?
receive side, come from ER and face it.
What is Trans Face?
Shipping side, faces plasma membrane.
What are the 3 sequences of events from protein synthesis on the rough ER to the final distribution of those protein in the golgi apparatus?
- Protein containing vesicles pinch off rough ER and migrate to fuse with membranes of golgi apparatus.
- Proteins are modified within the golgi compartments.
- Proteins are then packaged within different vesicle types, depending on their ultimate destination.
What 3 things can happen to a protein vesicle once it leaves the golgi apparatus?
- To to exocytosis
- Secretion
- Incorporated into plasma membrane as lysosomes.
These are spherical membranous organelles containing activated digestive enzymes. They are large and abundant in phagocytes, the cells that dispose of invading bacteria and cell debris. Also called the “demolition crew”
Lysosomes
In what 4 ways do lysosomes provide sites where digestion can proceed safely within a cell?
- Digesting particles taken in by endocytosis, particularly ingested bacteria, viruses, and toxins.
- Degrading stressed or dead cells and worn out or non functioning organelles, a process more specifically called autophagy (“self-eating”)
- Performing metabolic functions such as glycogen breakdown and release.
- Breaking down bone to release calcium ions into the blood .
This is a system of organelles that work together to produce, degrade, store, and export biological molecules and degrade potentially harmful substances.
Endomembrane System
What organelles are part of the endomembrane system?
Endoplasmic Reticulum Golgi Apparatus Secretory Vesicles Lysosomes Nuclear Membrane
This is the “cell skeleton”. It is a network of rods running through cytosol and hundreds of accessory proteins that link these rods to other cell structures.
Cytoskeleton
What are the 3 parts of the cytoskeleton?
- Microfilament
- Intermediate Filament
- Microtubule
This is the thinnest element of the cytoskeleton. They are strands made of spherical protein subunits called actin.It is the most changeable
Microfilament
What do microfilament attach to?
Cytoplasmic side of plasma membrane to give it strength.
Actin are round proteins, together they are called_____ by themselves they are called____.
Fibrous actin
Globular actin
These are tough insoluble protein fibers that resemble woven ropes composed of tetramer (4) fibers. They are the most stable of the cytoskeleton.
Intermediate filaments.
Where do intermediate filaments attach?
Attach to desmosomes and serve to resist mechanical strain on cells.
These are hollow tubes of spherical protein subunits called tublin. They give shape to the cell and anchor organelles. They use protein motors to move large objects through the cell like an elevator.
Microtubules.
Where do microtubules attach to?
They radiate out from the centrosome.
Inconspicuous region near the nucleus. This acts as a microtubule organizing center and contains paired centrioles.
Centrosome.
These are small barrel shaped organelles oriented at right angle to each other. Consists of a pinwheel array of nine triplets of microtubules. They also form the bases of cilia and flagella.
Centrioles.
These are whiplike motile cellular extensions that occur typically in large numbers on the exposed surface of certain cells.
Cilia
What are cilia made of?
Centrioles
These are longer cilia used to propel the cell. Like the tails of sperm.
Flagella
___ move fluid through cell.
Cilia
____ move cell through fluid.
Flagella
Centrioles forming the bases of cilia and flagella are called?
Basal Bodies
This is the gene containing control center of the cell and the largest organelle.
Nucleus
What are the 3 parts of the nucleus?
- Nuclear envelope
- Nucleoli
- Chromatin
Cells that have many nuclei such as liver, skeletal muscle cells, and bone destruction cells.
Multinucleate
Cells that cannot reproduce and therefore live in the bloodstream for only 3-4 months before they deteriorate, such as red blood cells.
Anucleate
This is a double membrane barrier separated by a fluid filled space.
Nuclear envelope
The outer nuclear membrane is continuous with the ____.
Endoplasmic Reticulum
The inner nuclear membrane is lined by the nuclear ____.
Lamina
These are a network of protein lamins (rod shaped proteins that assemble to form intermediate filaments) used to maintain nuclear shape.
Lamina
The nuclear envelope is punctuated with these, which are an intricate complex of proteins that form an aqueous transport channel and regulate entry and exit of molecules and large particles into and out of the cell.
Nuclear Pores (nuclear pore complex)
These are dark spherical bodies where ribosomal subunits are assembled.
Nucleoli
How many nuclei per nucleus?
typically 1-2 but there may be more
____ are usually large in growing cells that are making large amounts of tissue proteins.
Nucleoli
This is fine unevenly stained network of bumpy threads weaving through the nucleoplasm.
Chromatin
What is chromatin composed of?
30% DNA
60% globular histone proteins which package and regulate the DNA
10% RNA chains newly formed or forming.
What are the fundamental units of chromatin?
Nucleosomes
These consist of flattened disc shaped cores or clusters of 8 histone proteins connected like beads on string by a DNA molecule.
Nucleosomes
Condensed chromatin for cell division is called?
Chromosomes
DNA to RNA proteins require what 3 parts?
- Replication
- Transcription
- Translation
Replication and transcription of DNA to RNA occur where?
In the nucleus
Translation of RNA to a protein occurs where?
In ribosomes
What is Replication?
Cell division or duplication of DNA so that the next generation can produce proteins
This transfers information from DNA base sequence to complementary base sequence of an mRNA molecule. One it is made it detaches ad leaves the nucleus via a nuclear pore and heads for the protein synthesis machinery, the ribosome.
Transcription
What is Translation?
The language of nucleic acids (base sequences) is translated into the language of proteins (amino acid sequence).
What are the 3 types of RNA necessary for translation?
- Messenger mRNA
- Ribosomal rRNA
- Transfer tRNA
This is a small cloverleaf shape, used for protein manufacturing and is attached to an amino acid
Transfer tRNA
This encodes genetic information to be translated into proteins. Copy of DNA with instructions on how to make protein.
Messenger mRNA
What are the 3 basic phases of Transcription?
- Initiation
- Elongation
- Termination
Step one in Transcription where The RNA polymerase pulls apart the strands of DNA double helix so transcription can begin at the start point in the promoter.
Initiation
Step 2 in Transcription where incoming RNA nucleotides substrates and aligns RNA polymerase with complimentary DNA bases on the template strand and then links them together.
Elongation
Step 3 in Transcription when the polymerase reaches a special base sequence called a termination signal, transcription ends and the newly formed mRNA separates from the DNA template.
Termination
What are the 3 stop sequences?
UAA
UGA
UAG
What is the start sequence?
AUG
What is AUG?
Methionine
When does translation start?
When methionine bound tRNA recognizes a start codon AUG.
When does translation stop?
At the stop codons UGA, UAA, UAG
Ribosomes have 3 sites for tRNA, what are they? They all allow a ribosome to look at a codon and find the anticodon.
- Aminoacyl (A) for incoming tRNA
- Peptidyl (P) for adding polypeptides
- Exit (E) for outgoing tRNA
What is the sequence of events in Translation?
- Initiation
- Elongation
a. codon recognition
b. peptide bond formation
c. translocation - Termination