62 terms

Ch 6: A Tour of the Cell - Part 1

Campbell Biology 9e
All organisms are made of what
The cell is the ________ collection of matter that can be alive.
cellular function
The cell function is correlated to what?
descent from earlier cells
How are all cells related?
Though usually too small to be seen by the unaided eye, cells can be complex __________.
Light Microscope (LM)
Visible light is passed through a specimen and then through glass lenses
refract (bend)
What do the lenses on a LM do to the light in order to magnify the image?
Magnification, resolution, contrast
What are three important parameters of microscopy?
The ratio of an object's image size to its real size
The measure of the clarity of the image, or the minimum distance of two distinguishable points
Visible differences in parts of the sample
1,000 times
LMs can magnify effectively to about how much of the size of the actual specimen
stained or labeled
Various techniques enhance contrast and enable cell components to be _________ or _________.
Most subcellular structures, including what, are too small to be resolved by an LM
Subcellular structures
Two types of electron microscopes are used to study what?
Scanning electron microscopes (SEM)
Focus a beam of electrons onto the surface of a specimen, providing images that look 3-D
Transmission electron microscopes (TEMs)
Focus a beam of electrons through a specimen
internal structures
TEMs are mainly used to study what part of cells?
Prokaryotic or eukaryotic
The basic structural and functional unit of every organism is one of two types of cells:
Bacteria and Archaea
Only organisms of the domains ________ and ________ consist of prokaryotic cells
Protists, fungi, animals, and plants
Which organisms consist of eukaryotic cells
Plasma membrane, semifluid called cytosol, chromosomes, and ribosomes
What are the basic features of all cells?
Prokaryotic cells
Are characterized by having no nucleus, DNA in an unbound region called the nucleoid, no membrane-bound organelles, and Cytoplasm bound by the plasma membrane
Eukaryotic cells
Are characterized by DNA in a nucleus that is bounded by a membranous nuclear envelope, membrane-bound organelles, and cytoplasm in the region between the plasma membrane and nucleus
much larger
Eukaryotic cells are generally ______ ________ than prokaryotic cells
Plasma membrane
A selective barrier that allows sufficient passage of oxygen, nutrients, and waste to service the volume of every cell
double bilayer
The general structure of a biological membrane is a ________ _________ of phospholipids.
What type of requirements set upper limits on the size of cells?
surface area to volume
What ratio is critical to a cell?
internal membranes
A eukaryotic cell has _______ ________ that partition the cell into organelles
Plant and animal
What organisms have most of the same organelles.
Nucleus; DNA
The ________ contains most of the ______ in a eukaryotic cell
What uses the information from the DNA to make proteins?
Contains most of the cell's genes and is usually the most conspicuous organelle
Nuclear envelope
Encloses the nucleus, separating it from the cytoplasm
double membrane
The nuclear membrane is a _______ ________; each membrane consists of a lipid bilayer
What regulates the entry and exit of molecules from the nucleus?
Nuclear lamina
What is the shape of the nucleus maintained by and is composed of proteins?
In the nucleus, DNA is organized of a single DNA molecule called what?
a single DNA molecule
Each chromosome is composed of what and is associated with proteins?
The DNA and proteins of chromosomes are together
Discrete Chromosomes
Chromatin condenses to form what as a cell prepares to divide?
Located within the nucleus and is the site of ribosomal RNA(rRNA) synthesis
Particles made of ribosomal RNA and protein
cytosol (free ribosomes) and on the outside of the endoplasmic reticulum or the nuclear envelope (bound ribosomes)
Ribosomes carry out protein synthesis in two locations
Rough ER has what?
nuclear envelope, endoplasmic reticulum, golgi apparatus, lysosomes, vacuoles, plasma membrane
Components of the endomembrane system
Endomembrane system components are either continuous or connected via transfer by what?
Biosynthetic Factory
The Endoplasmic Reticulum
Endoplasmic reticulum
Accounts for more than half of the total membrane in many eukaryotic cells
The ER membrane is what with the nuclear envelope?
Smooth ER (lacks ribosomes) and rough ER (surface is studded with ribosomes)
What are the two distinct regions of ER?
Smooth ER
Synthesizes lipids, metabolizes carbohydrates, detoxifies drugs and poisons, and stores calcium ions
Proteins covalently bonded to carbohydrates
Rough ER
has bound ribosomes (which secrete glycoproteins), distributes transport vesicles, and is a membrane factory for the cell
Transport vesicles
Proteins surrounded by membranes
A membranous sac of hydrolytic enzymes that can digest macromolecules
Lysosomal enzymes
Can hydrolyze proteins, fats, polysaccharides, and nucleic acids
acidic environments
Lysosomal enzymes work best in what environment inside the lysosome?
Some types of cells can engulf another cell by what, forming a food vacuole?
food vacuole
A lysosome fuses with what and digest the molecules?
Lysosomes also use enzymes to recycle the cell's own organelles and macromolecules, a process called what?