Bio: Cells 2
demonstrate the relationship between surface area and volume.
A large, round cell has a lower surface area to volume ratio than a thin, flat cell. Cellular extensions increase the cell's surface area to volume ratio. Root hairs, flat leaves, and feathery gills increase surface area.
Golgi apparatus
A system of membranes that modifies and packages proteins for export by the cell
Membrane
All cells have a cell __________ , that surrounds the cytoplasm and forms a boundary between the cell and its environment.
Choice, centrioles present centrioles present
Animal Cell
In cell membranes, the phospholipids are arranged into a
Bilayer
lipid-rich boundary between the cells and outside environment
Cell membrane
Eukaryotic cells
Cells that contain membrane-bounded organelles and a nucleus
Types of light microscope
Confocal and Compound
all cell contents except the nucleus
Cytoplasm
the cell's genetic information
DNA
how DNA in the nucleus is used to specify protein production by the cell.
DNA is copied into mRNA in the nucleus, and the mRNA is used outside the nucleus to make proteins.
Rudolph Virchow
Discovered all cells come from other cells
What is a network of sacs and tubules extending off the nuclear envelope and is where proteins and lipids are produced?
Endoplasmatic Reticulum
Peroxisomes are organelles that originate at the ______ and contain enzymes that dispose of toxic substances.
Endoplasmatic reticulum
Protists, plants, fungi, and animals are organisms in the domain
Eukarya
The ______ is a series of flattened sacs that sorts and packages materials into vesicles to be sent to the cell membrane.
Golgi Apparatus
Lysosomes originate from vesicles that bud from the ______, and the enzymes contained in lysosomes are synthesized in the ______.
Golgi apparatus; rough ER
attach to the endoplasmic reticulum.
If an mRNA specifies a protein to be used in the cell membrane or to be secreted from the cell, this protein is made on ribosomes that
cell with more surface area relative to volume
What cell shape has the most efficient exchange of materials between the cell's interior and exterior?
Peroxisomes
What organelle protects all eukaryotic cells from toxic substances or toxic by-products of chemical reactions?
Description of a confocal microscope
White or laser light is focused through a lens, and the image passes through a pinhole.
Eukarya
possible larger cell size, fatty acids in the cell membrane, and nucleus present
contractile vacuole in Paramecium matches
pump excess water out of the cell
roles that membranes play in cells.
receive and respond to external stimuli enclose organelles in eukaryotic cells transport substances into and out of the cell
Proteins to be secreted outside of a eukaryotic cell are formed at ribosomes on the surface of the ______ endoplasmic reticulum.
rough
What plant cell organelle can occupy up to 90% of the cell volume and can exert turgor pressure against the cell membrane when it acquires water?
central vacuole
Choice, contains enzymes, salts, pigments, sugars, and acids contains enzymes, salts, pigments, sugars, and acids
central vacuole in plants
differ between domains Bacteria and Archaea.
chemical composition of flagella molecules that compose the cell membranes evolutionary relationship to eukaryotes
present in plant cells but not in animal cells.
chloroplasts cell wall
The two-layered nuclear envelope separates the nucleus of a cell from the
cytoplasm
Organelles called lysosomes contain ______ that break down food particles, old organelles, and other cellular debris.
enzymes
Bacteria
small cell size, fatty acids in the cell membrane, and prokaryotic
Archaea
small cell size, nonfatty acid lipids in the cell membrane, and prokaryotic
Lipids, detoxifying enzymes, and membrane components are produced and stored in the ------------ endoplasmic reticulum.
smooth
What is the function of mitochondria in eukaryotic cells?
extract energy from food
Nuclear pores
holes in the nuclear envelope that allow materials to pass in and out of the nucleus
functions of the smooth endoplasmic reticulum.
house enzymes that detoxify drugs and poisons synthesize lipids
The head of a phospholipid is ______, meaning its polar covalent bonds attract water, but the tails of a phospholipid are ______ and thus water-insoluble.
hydrophilic; hydrophobic
Nuclear envelope
layer of two membranes that surrounds the nucleus of a cell
ways that cells avoid surface area limitations.
long or thin shape efficient transportation system within cell
functions of lysosomes.
lyse captured bacteria breakdown large food particles into smaller subunits dismantle worm-out organelles
Archaeans called methanogens use carbon dioxide and hydrogen from the environment and produce ______ as a byproduct
methane
electron
microscope allows resolution of objects that are about 5 nanometers in size
about prokaryotes.
most ancient forms of life on Earth simplest types of life lack a nucleus
characteristics of eukaryotic cells.
nucleus larger than prokaryotic cells system of internal membranes
components of the cytoplasm
organelles cytosol ions and enzymes cytoskeleton
components of phospholipid molecules
two fatty acids phosphate group glycerol molecule
The enzymes in one lysosome could not digest a cell because the ______ of the lysosome is much ______ than the neutral cytoplasm, and therefore the lysosome enzymes would not be able to function fully in the cell cytoplasm.
pH
describe compound microscopes.
type of light microscope uses two or more lenses to focus visible light commonly used in biology lab courses
describe electron microscopes
use beam of electrons instead of light provide greater magnification than light microscopes usually require that specimen be killed expensive to build and operate
The protein produced by a free ribosome (left panel) will most likely be ______, while the protein produced by a ribosome attached to the rough ER's membrane (right panel) will most likely be ______.
used in the cytosol; used in the cell membrane
Plant cells have large central ______ where water, salts, and sugars are stored and where materials are broken down and recycled with enzymes similar to lysosomes in animal cells.
vacuoles
Turgor pressure in plant cells results from the expansion of the central vacuole as it fills with
water
Lysosomes are often required to process ______, which reach toxic levels in the brain cells of people with malfunctioning lysosomes (a condition called Tay-Sachs disease).
Lipids
What organelle of the endomembrane system breaks down debris, food, and old cell parts with special dismantling enzymes?
Lysosome
examples in which the ratio of surface area to volume of cells is increased.
Nerve cells are long and thin. Amoebas have extensions of their cell membrane. Paramecia are horizontally flattened in shape.
The ______ found within the nuclear envelope are lined with specialized proteins that allow the transport of substances into and out of the nucleus.
Nuclear pores
allow the passage of regulatory proteins into the nucleus and mRNA molecules out of the nucleus?
Nuclear pores
membrane
Organelles carry out specialized functions in the cell and are enclosed by
Eukarya
Organisms in the domain ______ are made of cells that have a nucleus and membranous organelles.
cell wall and chloroplasts present
Plant Cell
In all cells, RNA and ribosomes play a role in the production of ______, which are molecules that carry out all of the cell's work.
Proteins
What cell structure binds to mRNA coming from the nucleus and manufactures proteins?
Ribosome
structures that manufacture proteins
Ribossome
Light
The ______ microscope is ideal for viewing living cells that are between 200 nanometers and 1 millimeter in size.
transmission; scanning
Two types of electron microscopes are ______ electron microscopes, which pass electrons through a specimen, and ______ electron microscopes, which beam electrons over the surface of a metal-coated specimen.
In the Golgi apparatus, proteins are sorted and packaged into ______ that deliver the proteins to their destinations.
Vesicles
Cytosol
The watery mixture of ions, enzymes, and RNA within the cytoplasm is called the
Based on Carl Woese's work, biologists recognized _____ domains of life.
Three
Most cells have a small size that is less than 0.1 mm in diameter to maximize surface area relative to volume.
True
Enzymes in the lysosomes function at a more ______ pH than the cytoplasm, which means the enzymes only function within the enclosed lysosome, unless all of a cell's lysosomes burst at once.
acid
Enzymes in the Golgi apparatus can synthesize and attach ______ to proteins and lipids, forming glycoproteins and glycolipids.
carbohydrates
liver cells white blood cells
cells that have relatively more lysosomes.