Chapter 4 Flashcards
What is the difference between a prokaryotic and eukaryotic cell?
A eukaryotic cell has a true nucleus, membrane-bound organelles and is larger and more complex than the prokaryotic cell (prokaryotic cell 1/10 the size). In a prokaryotic cell, DNA has to be kept in the nuceloid region
what things do all cells have in common?
a plasma membrane, ribosomes, and DNA as hereditary material
what are some structures of the prokaryotic cell?
there may be a fairly rigid cell wall outside plasma membrane. there may be a capsule, a fairly sticky outer coat that surrounds cell wall and helps glue prokaryotes to surfaces. pili also help it attach. finally, it may have a flagella, which is usually only 1 and helps propel prokaryotic cell thr liquid environment
what are some additional names for the plasma membrane?
cell membrane/ phospholipid biilayer
what is the function of the cell membrane?
it acts as a barrier between the inside and outside of cell “gatekeeper”
why is the cell membrane described as a fluid mosaic model?
it acts more like a liquid than a solid. it is like a mosaic because it is made up of many different pieces
what is the cytoplasm?
fluid-filled interior of the cell contained by plasma membrane. holds cytoskeleton and all organelles except for nucleus
name and describe the parts of the nucleus
nuclear envelope- double membrane separating nucleus from cytoplasm
nuclear pores- tiny, protein-lined holes in nuclear envelope that allow substances like RNA to pass through
nucleolus- central region of nucleus where building blocks of ribosomes are produced
nucleoplasm- jelly-like liquid that fills nucleus
what are the functions of the nucleus?
it’s a control center for the eukaryotic cell; contains genetic material (DNA) which directs protein synthesis
what does the DNA in the nucleus look like?
DNA is attached to proteins that form long fibers called chromatin. Each chromatin fibers a chromosome (DNA is in chromatin form when cell is not dividing, but in form of chromosomes when it is
what is the golgi apparatus and what is its function?
it takes in and modifies, chemically, the substances created by the ER. it finishes, stores and then ships cell products to different destinations through the use of vesicles
what is a flagellum and what is its function
long, whiplike structure that sticks out from the cell’s surface. not as many per cell as cilia. its function is to aid the cell in movement
what are cilia and what is their function
they are short, hair-like projections that occur in copious amounts. they aid cell in movement.
what are ribosomes, where are they found and what is their function?
ribosomes are small, roughly spherical subunits made of protein and RNA. they are where proteins are made and are found in the cytoplasm or on the Roiugh ER.
what are lysosomes and what is their function
they are spherical membranous organelles that contain digestive enzymes, so they help break things down. contain acidic environment isolated from the test of cytoplasm. they are types of vesicles, small, membrane-bound sacs that transport substances in cells
what are some examples of lysosome digestive functions?
protist engulf food into food vacuoles, in which lysosomes break down food releasing nutrients to the cell. white blood cells ingest bacteria which lysosome enzymes rupture. lysomes fuse with damaged organelles to recycle their contents and allowing organic molecules to be re-available for use