Term
All organisms made are of
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Definition
| the simplest collection of matter that can live |
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Term
Cell structure is correlated
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Definition
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Term
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Definition
| their descent from earlier cells |
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Term
To study cells, biologists use
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Definition
microscopes and the
tools of biochemistry |
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Term
The quality of an image depends on
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Definition
–
Magnification
its real size
, the ratio of an object’s image size to
– Resolution
or the minimum distance of two distinguishable
points, the measure of the clarity of the image,
–Contrast
visible differences in parts of the sample
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Term
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Definition
1,000 times the size of the actual specimen
- can enhance contrast by staining
Most subcellular structures, including organelles, are too small to be resolved by an LM |
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Term
Scanning electron microscopes (SEMs)
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Definition
focus a beam ofelectrons onto the surface of a specimen, providing imagesthat look 3-D (external surfaces) |
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Term
Transmission electron microscopes (TEMs)
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Definition
focus a beam of electrons through a specimen
- TEMs are used mainly to study the internal structure of cells |
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Term
The basic structural and functional unit of every organism is one of
two types of cells |
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Definition
| prokaryotic or eukaryotic |
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Term
| Only organisms of the domains Bacteria and Archaea consist of |
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Definition
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Term
| Protists, fungi, animals, and plants all consist of |
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Definition
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Term
| All cells have the following: |
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Definition
– Plasma membrane
– Semifluid substance called cytosol
– Chromosomes (carry genes)
– Ribosomes (make proteins) |
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Term
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Definition
– No nucleus
– DNA in an unbound region called the nucleoid
– No membrane-bound organelles
– Cytoplasm bound by the plasma membrane |
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Term
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Definition
– DNA within a nucleus surrounded by a membranous nuclear
envelope
– Membrane-bound organelles
– Cytoplasm in the region between the plasma membrane and
nucleus
Eukaryotic cells are generally much larger than prokaryotic cells |
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Term
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Definition
selective barrier that allows
the passage of oxygen, nutrients, and waste into and out
of the cell
• A phospholipid bilayer |
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Term
| The Nucleus: Information Central |
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Definition
• The nucleus contains most of the cell’s genes and is usually
the most conspicuous organelle
• The nuclear envelope encloses the nucleus, separating it from
the cytoplasm
• The nuclear membrane is a double membrane; each
membrane consists of a lipid bilayer |
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Term
| Ribosomes use the information from |
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Definition
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Term
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Definition
| what goes in or out of the nucleus |
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Term
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Definition
| maintains the shapeof the nuclues and is composed of protein |
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Term
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Definition
| In the nucleus, DNA and proteins form genetic material chromatin which forms chromosons |
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Term
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Definition
within the nucleus and is the site of
ribosomal RNA (rRNA) synthesis |
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Term
| Ribosomes are particles made of |
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Definition
| ribosomal RNA and protein |
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Term
| Ribosomes carry out protein synthesis in two locations: |
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Definition
– In the cytosol (free ribosomes)
– On the outside of the endoplasmic reticulum or the nuclear envelope (bound ribosomes) |
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Term
| The endomembrane system regulates |
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Definition
| protein traffic and performs metabolic functions in the cell |
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Term
Components of the
endomembrane
system: |
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Definition
– Nuclear envelope
– Endoplasmic
reticulum
– Golgi apparatus
– Lysosomes
– Vacuoles
– Plasma membrane |
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Term
| The endoplasmic reticulum (ER) accounts for |
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Definition
| more than half of the total membrane in many eukaryotic cells |
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Term
| The ER membrane is continuous |
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Definition
| with the nuclear envelope |
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Term
| There are two distinct regions of ER: |
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Definition
– Smooth ER, which lacks ribosomes
– Rough ER, with ribosomes studding its surface |
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Definition
- synthesizes lipids
- metabolizes carbohydrates
- detoxifies poison
- stores calcium |
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Term
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Definition
– Has bound ribosomes that secrete glycoproteins (proteins
covalently bonded to carbohydrates)
– Distributes transport vesicles (proteins surrounded by
membranes)
– The membrane factory for the cell |
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Term
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Definition
| : Shipping and Receiving Center |
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Term
| The Golgi apparatus consists of |
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Definition
flattened membranous sacs called
cisternae |
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Term
| Functions of the Golgi apparatus: |
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Definition
– Modifies products of the ER
– Manufactures certain macromolecules
– Sorts and packages materials into transport vesicles |
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Term
| The Golgi apparatus has two sides: |
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Definition
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Term
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Definition
| membranous sac of hydrolytic enzymes |
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Term
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Definition
- digests macromolecules
- these enzymes can hydrolyze proteins, fats, polysaccharides,
and nucleic acids |
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Term
| Lysosomes also use enzymes |
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Definition
to perform recycle the cell’s own
organelles and macromolecules, a process called autophagy; also
undergoes phagocytosis (eats solid particles) |
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Term
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Definition
| - isolate harmful materials, contain waste |
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Term
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Definition
| are formed by phagocytosis |
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Term
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Definition
Contractile vacuoles, found in many freshwater protists,
pump excess water out of cells |
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Term
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Definition
found in many mature plant cells, hold
organic compounds and water |
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Term
| The endomembrane system is a |
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Definition
complex and dynamic
player in the cell’s compartmental organization |
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