Chapter 6: A Tour Of The Cell Flashcards
Define Organelles
Any of several membrane-enclosed structures with specialized functions, suspended in the cytosol of eukaryotic cells.
Define Cell Fractionation
The disruption of a cell and separation of its parts by centrifugation at successively higher speeds.
______ cells have internal membranes that compartmentalize their functions.
Eukaryotic
What are some basic features that all cells share?
They are all bounded by a plasma membrane (also referred to as the cell membrane)-All cells contain chromosomes-All cells have ribosomes. MCR. (Membrane-Chromosome-Ribosome)
Define Cytosol
The semi fluid portion of the cytoplasm.
Define Eukaryotic Cell
A type of cell with a membrane-enclosed nucleus and membrane-enclosed organelles.
Define Prokaryotic Cell
A type of cell lacking a membrane-enclosed nucleus and membrane-enclosed organelles. Organisms with prokaryotic cells (bacteria and archaea) are called prokaryotes.
Define Nucleoid
A non-membrane enclosed region in a prokaryotic cell where its chromosome is located.
What is the major difference between Prokaryotes and Eukaryotes?
In a eukaryotic cell, most of the DNA is in an organelle called the nucleus, which is bounded by a double membrane. In a prokaryotic cell, the DNA is concentrated in a region that is not membrane-enclosed called the nucleoid.
Define Cytoplasm
The contents of the cell bounded by the plasma membrane; in eukaryotes, the portion exclusive of the nucleus.
What is another difference between eukaryotes and prokaryotes?
Absence of membrane-bound organelles-Eukaryotes are Larger
Define Plasma Membrane
The membrane at the boundary of every cell that acts as a selective barrier, regulating a cell’s chemical composition.
A smaller object has a greater ratio of _____ to _____.
Surface Area-Volume
Enzymes embedded in the membranes of the organelles called mitochondria function in _____.
Cellular Respiration
The eukaryotic cell’s giant instructions are housed in the _____ and carried out by the _____
Nucleus-Ribosomes
Define Nucleus
The organelle of a eukaryotic cell that contains the genetic material in the form of chromosomes, made of chromatin.
Define Nuclear Envelope
In eukaryotic cells, the double membrane that surrounds the nucleus, perforated with pores that regulate traffic with the cytoplasm. The outer membrane is continuous with the endoplasmic reticulum.
The nuclear envelope is a _____ membrane. The two membranes, each a lipid bilayer with associated proteins, are separated by a space of _____ to _____ nanometers.
Double; 20-40
What is the role of pore complex?
A pore complex is an intricate protein structure that lines each pore and plays an important role in the cell by regulating the entry and exit of proteins and RNAs, as well as large complexes of macromolecules.
Define Nuclear Lamina
A netlike array of protein filaments that lines the inner surface of the nuclear envelope and helps maintain the shape of the nucleus.
Define Chromosomes
A cellular structure consisting of one DNA molecule and associated protein molecules. In eukaryotic cells, chromosomes are linear and located in the nucleus. In prokaryotes, chromosomes are circular and located in the nucleoid.
Define Chromatin
The complex of DNA and proteins that makes up eukaryotic chromosomes.
How many chromosomes are in a typical human cell? What types of cells are the exceptions?
46-Sex Chromosomes-23
Define Nucleolus
A specialized structure in the nucleus, consisting of long chromosomal regions containing ribosomal RNA genes along with the ribosomal proteins imported from the cytoplasm.