Chapter 4 Flashcards
Magnification
The ratio of an objects image size to its real size
Resolution
The measure of the clarity of the image; it’s the minimum distance two points can be distinguished.
Contrast
The difference in brightness between the light and dark areas of an image
Organelles
Membrane bound structures within eukaryotic cells
Electron microscope
Focusses a beam of electrons through the specimen or onto its surface. Electron microscopes Can see bacteria, proteins, lipids, and organelles
Describe the following
- unstained specimen
- phase contrast
- fluorescence
- confocal
Little contrast
Enhances contrast but kills specimen
Labels molecules with fluorescent dyes which absorb ultra violet light
Sections the fluorescent molecules to create 3D view
Plasma membrane
The membrane at the boundary of every cell that acts as a selective barrier, regulating the cells chemical composition.
What does the plasma membrane have in or on it?
Enzymes in them, embedded are lipids and proteins
Describe some key features of the nucleus
- contains most of the genes in Eu. Cells
- most noticeable structure
- has nuclear envelope with nuclear pores
- nuclear lamina: netlike array of protein filaments that maintains shape of the nucleus by supporting the envelope
- chromosomes are wrapped in proteins to coil them and reduce length. (Chromatin)
Nucleolus
A specialized structure in the nucleus consisting of chromosomal regions containing ribosomal RNA genes along with ribosomal proteins imported from the cytoplasm; site of RNA synthesis and ribosomal subunit assembly.
Ribosomes
Are they membrane bound?
A complex of rRNA and protein molecules that functions as a site of protein synthesis Im the cytoplasms: consists of a large and small subunit. In euk. Cells subunit is assembles int he nucleolus.
Not bound= not organelles
What are the two types of ribosomes
Free- suspended in cystol( proteins made are made for cystol)
Bound- attached outside of rough ER or nuclear envelope. Make proteins to be in membranes within certain organelles. Exm. Lysosomes
Endomembrane system and its consisting parts
Regulates protein traffic and performs metabolic functions. Includes plasma membrane, nuclear envelope, smooth and rough ER, Golgi apparatus, lysosomes, vesicles and vacuoles.
It synthesizes proteins, transports proteins into membrane or organelles in or out of cell, metabolism, movement of lipids and detoxification of poisons.
What are all the parts of the endomembrane system connected by!
Vesicles: a membranous sac I’m the cytoplasm of Euk. Cells.
What is the endoplasmic reticulum?
An extensive membranous network in Euk. Cells continuous with the outer nuclear membrane and composed of ribosome-studded (rough) and ribosome free (smooth) regions.
What is the smooth ER responsible for?
Functions may include synthesis of lipids, metabolism of carbs, detoxification of drugs and poisons (addition of hydroxyl group),and calcium ion storage. Enzyme here. Synthesis lipids;oils, steroids, new membrane phospholipids.
What is the rough ER responsible for?
Produces proteins that cells secrete
Glycoproteins- proteins with carbohydrates covalently bonded
Transfer proteins with transport vesicles
Membrane factory for cells; grows in place by adding membrane proteins and phospholipids to self. Makes hydrologic enzymes
What is the function of the Golgi apparatus?
(Shipping and receiving)
Products of ER are modified, stored and sent out.
Manufacturing some macromolecules (polysaccharides)
What makes up the Golgi and what do they have?
Cisternas layers that have inferential enzymes for different functions.
Lysosomes
Where do enzymes here work best?
A membranous-enclosed sac of hydrologic enzymes found in the cytoplasm of animal cells and some plants that are used to digest (hydrolyze) macromolecules.
=inside the acidic environment of lysosomes.