Chapter 6 Flashcards
(35 cards)
What is Microscopy?
It makes small objects/items bigger
What are the different types of Microscopy?
Light Microscopy: visible light is passed through the specimen and then through the glass Ex: Most plant and animal cells, nucleus, bacteria, and Mitochondria
Electron Microscopy: Focuses a beam of electrons through a specimen or onto its surface Ex: Smallest bacteria, viruses, ribosomes, proteins, lipids, small molecules, and atoms
What is Resolution?
The measure of the clarity of the image
What is Contrast?
The difference between light and dark areas of an image
What is a Scanning Electron Microscope and a Transmission Electron Microscope?
Scanning: Focuses a beam of electrons that scans the surface of a specimen, used for detailed study of the topography of a specimen
Transmission: Aims an electron beam through very thin sections of a specimen, used for studying the internal structure of cells
What is Cell Fractionation?
A useful technique for studying cell structure and function
What is a Eukaryotic cell, what are its Domains?
It has a cell membrane and membrane-bound organelles, its domains are protists, fungi, animals, and plants
DNA is in the nucleus which is bounded by a double membrane
What is a Prokaryotic cell, what are its Domains?
It has free-floating organelles that float in the cytoplasm and doesn’t have a cell membrane, its domains are archaea and bacteria
DNA is in a nucleoid that is concentrated in a region that is not membrane closed but instead have proteins cutting off areas
What are cells? What do different types of cells have in common?
They are all bounded by the plasma membrane/cell membrane
Cytosol: Semifluid, jelly-like substance that suspends subcellular components,
All cells contain chromosomes and ribosomes and have cytoplasm
What are the functions of the Plasma Membrane?
It functions as a selective barrier that allows the passage of enough oxygen, nutrients, and waste to service the cell also participates directly in a cell’s metabolism
What is the Surface area to Volume for Cells?
As a cell increases in size, its surface area increases less than the volume
A smaller cell has a greater ratio of surface area to volume
Microvilli: Increase surface area without a huge increase of volume
What are the Nucleus and Envelope? What are their functions?
Nucleus: Contain most of the genes of the cell
Envelope: Encloses the Nucleus and separates it from the Cytoplasm is also a double membrane
What is a Pore Complex?
Pore Complex: lines each pore on the envelope and regulates the entry and exit of proteins, RNA´s and large complexes of macromolecules
What is the Nuclear Lamina? What is its function?
It lines the Nuclear side of the envelope, it is a netlike array of protein filaments that maintains the shape of the nucleus by supporting the nuclear envelope
What are Chromosomes? Where are they in a cell?
They are units of organized DNA in the nucleus, contains one long DNA molecule associated with many proteins, including small basic proteins called histones
What is Chromatin?
The complex of DNA and proteins making up chromosomes
What is Nucleoli? Where is it found? What does it do?
It is a mass of densely stained granules and fibers adjoining a part of the chromatin
It may play a role in controlling cell division and the life span of a cell
It is found in the nucleus and is made out of a type of RNA called ribosomal RNA, they play a role in ribosome assembly
What is a Ribosome? What are its functions?
Ribosomes are complexes made of ribosomal RNAs and proteins, they are not membrane-bound
They carry out protein synthesis and build proteins
What are the different types of Ribosomes?
Free Ribosomes: suspended in the cytosol
Bound Ribosomes: attached to the outside of the endoplasmic reticulum or nuclear envelope,
What is the function of Bound Ribosomes?
They make proteins that are destined for insertion into membranes and for packaging with certain organelles like lysosomes or exporting things from the cell
What organelles are a part of the Endomembrane System for a Eukaryotic cell?
Nuclear envelope, the endoplasmic reticulum, the Golgi apparatus, lysosomes, various kinds of vesicles and vacuoles, and the plasma membrane
What is the Endoplasmic Reticulum? What are its functions?
It is an extensive network of membranes, consists of a network of membranous tubules and sacs called cisternae
It separates the internal compartment of the ER (Lumen) from the cytosol
What is the difference between the smooth and rough ER?
Smooth: Its outer surface lacks ribosomes, involved in the synthesis of lipids, metabolism of carbohydrates, detoxification of drugs and poisons, and storage of calcium ions.
Rough: Is studded with ribosomes on the outer surface of the membrane
What are Glycoproteins?
They are proteins with carbohydrates covalently bonded to them
