7.3 Flashcards
Nucleus
A membrane enclosed organelle in all eukaryotic cells. Contains the cells DNA and maintains the integrity of genes and controls the activities of the cell by regulating gene expression.
Nuclear envelope
A double membrane enclosing the nucleus from the surrounding cytoplasm and rest of cell
nucleoskeleton
a network inside the nucleus that adds mechanical support and structure
nuclear pores
channel for transport through the nuclear envelope. large molecules and proteins are carried by carrier proteins. proteins and RNA need to move through these pores for gene expression and chromosome maintenance
nucleolus
A sub nuclear body in the interior of the nucleus. involved in the assembly of ribosomes
interior of the nucleus
contains non uniform sub nuclear bodies made of RNA, Proteins and specific parts of chromosomes
Endogenous Membrane System
An organelle in cells formed as interconnected flattened membrane enclosed sacs called cisternae. The organelle surrounds the outer nuclear membrane
Cisternae
flattened membrane vesicle type that makes up the endogenous membrane system and the golgi apparatus
Smooth endoplasmic reticulum
help with lipid creation, metabolism, steroid production and detoxification. Smooth er is most present in cells that need high steroid production.
Rough endoplasmic reticulum
the outer membrane is studded with ribosomes that act as the site of protein synthesis
Ribosomes
produce most proteins in animal cells. (10 billlion)
Ribosome large sub unit function
Catalytical function. Contains Ribosomal RNA that acts as an enzyme and is called ribozyme
Ribosome small sub unit functions
decoding function. links up with mRNA first and then attaches to the larger sub unit
Ribosome sub units
Made of 2 sub units, one larger than the other. Made of proteins and nucleic acids from the nucleolus
Ribosome functions
Translate encoded information from the cell nucleus provided by mRNA
Links together amino acids from the cytoplasm using tRNA. They are then organized in proper gene that the mRNA holds instructions to
Exports the polypeptide made to the cytoplasm to be used as a protein
Are ribosomes static organelles
Ribosomes are not static organisms as they break down once they have done their job and produced the designated protein.
Polysome
The structure that makes it possible for ribosome sub units to process mRNA and produce polypeptides so quickly
Golgi apparatus
Membrane bound organelle made up of a series of cisternae. Responsible for transporting, modifying and packaging proteins and lipids into vesicles
moving from the cis face to the trans face of the golgi apparatus
proteins and lipids arrive at the cis face of the golgi through microtubules from the endoplasmic reticulum. once in the cis face, proteins and lipids are modified into functional proteins while moving towards the trans face. Molecules are packed into vesicles in the trans side of the golgi to be delivered where needed.
vesicular transport model
This theory states that vesicles bud off and deliver proteins to each cistaernae of the golgi apparatus. In this model the cis and trans faces constant and the golgi stays still
Cisternal maturation model
This model indicates that the cis cisternae move and mature into trans cisternae and they begin at the cis face from vesicle fusion. Vesices are only formed to move molecules to and from the golgi apparatus
vesicle
Constantly forming, membrane bound fluid filled sacs that aid in the transport of contents in and out of the cell
how are vesicles formed
Vesicles are formed when the membrane bulges out and pinches off into a vesicle.
Types of vesicles
Transport, secretory, lysosomes, peroxisomes, endosomes, phagosomes and vacuoles
How do vesicles move
Vesicles use the microtubules that make up the cytoskeleton to move through the cell and fuse to organelles when needed
Vacuoles
Large vesicles used as storage bubbles in cells
lysosomes function
The “digestive system of the cell” Lysosomes degrade materials from outside of the cells and also digest components of the cell itself when needed
lysosomes structure
Lysosomes are a type of double membraned vesicle. They contain enzymes capable of breaking down all types of polymers
What happens when a lysosome membrane bursts
The digestive enzymes in the lysosome are released into the cell and the cell dies
necrosis
Cell homocide from things like injury and infection
apoptosis
Cell suicide from the natural cell death program
