Biology 1001 Dr. Nita Exam 2 LSU QUESTIONS WITH
ANSWERS RATED A+
diffusion - - slow process by which molecules dissolved in fluids move
- all parts of cell must remain close to external environment to have access to nutrients and be
able to get rid of wastes
plasma membrane - - each cell surrounded by thin membrane
- encloses cell and allows interaction between cell and its environment
- consists of proteins embedded in bilayer of phospholipids
- two types of proteins: channel and receptor
channel proteins - allow specific molecules to pass into or out of cell
receptor proteins - bind messenger molecules and initiate cell's response to message
cytoplasm - - all cells contain it
- consists of all fluid and structures inside plasma membrane but outside nucleus in eukaryotes
cytosol - - fluid portion of cytoplasm
- contains water, salts, and organic molecules (proteins, carbohydrates, lipids, and sometimes
RNA)
cytoskeleton - - consists of variety of protein filaments
- filaments provide support, transport structures within the cell
- allows cell to move and change shape
- play a role in cell division
** Tubulin and Actin
DNA - - deoxyribonucleic acid
- hereditary instructions to form RNA
- encodes inherited set of instructions in segments called genes
genes - store instructions for making all parts of cell and for producing new cells
RNA - - DNA genes are copied to ribonucleic acid
- guides construction of cell parts and proteins
- helps construct proteins based on genetic instructions
- proteins constructed on ribosomes, cellular workbenches of specialized RNA called ribosomal
RNA
prokaryotic cells - - relatively simple internal structure
- generally less than 5 micrometers in diameter
, - unicellular
- make up two domains: Archaea and Bacteria
- specialized cytoplasmic structures (nucleoid and plasmids)
nucleoid - distinct region that contains single circular chromosome that consists of long, piled
strand of DNA
plasmids - small rings of DNA
prokaryotic cells' distinctive surface features - - nearly all surrounded by cell wall
cell wall - - provides protection and helps cell maintain its shape
- shapes may be rod-like, spiral, or spherical
gram positive - - thick peptidoglycan layer
- layer retains dye crystal violet
- also has teichoic acid
gram negative - - thin layer of peptidoglycan in periplasmic space
- contains thick lipopolysaccharide layer, which prevents crystal violet color to be retained by
cell
- cells can be seen by counterstain Safranin red dye
Bacillus anthrax - - gram postive bacteria
- vegetative cells showing retention of crystal violet
- can produce spores that survive about 48 years or more
- in US mail "2001 Anthrax scare"
pili (singular pilus) - - surface proteins (pilin) that project from cell walls of many bacteria
- two types of pili: attachment and sex
attachment pili - help bacteria adhere to surfaces
sex pili - form connections between adjacent bacteria that allow them to transfer plasmids
flagella (singular flagellum) - - some bacteria and archaea possess this
- extend from cell surface
- rotate and propel cell through fluid environment
- flagellin protein is principle component of bacteria flagella
Eukaryotic cells make up bodies of organisms in domain Eukarya - - contain organelles
membrane-enclosed structures specialized for a particular function
- organelles contribute to complexity of eukaryotic cells
extracellular matrix - function: surround cells, providing biochemical and structural support
- mostly absent in prokaryotes
ANSWERS RATED A+
diffusion - - slow process by which molecules dissolved in fluids move
- all parts of cell must remain close to external environment to have access to nutrients and be
able to get rid of wastes
plasma membrane - - each cell surrounded by thin membrane
- encloses cell and allows interaction between cell and its environment
- consists of proteins embedded in bilayer of phospholipids
- two types of proteins: channel and receptor
channel proteins - allow specific molecules to pass into or out of cell
receptor proteins - bind messenger molecules and initiate cell's response to message
cytoplasm - - all cells contain it
- consists of all fluid and structures inside plasma membrane but outside nucleus in eukaryotes
cytosol - - fluid portion of cytoplasm
- contains water, salts, and organic molecules (proteins, carbohydrates, lipids, and sometimes
RNA)
cytoskeleton - - consists of variety of protein filaments
- filaments provide support, transport structures within the cell
- allows cell to move and change shape
- play a role in cell division
** Tubulin and Actin
DNA - - deoxyribonucleic acid
- hereditary instructions to form RNA
- encodes inherited set of instructions in segments called genes
genes - store instructions for making all parts of cell and for producing new cells
RNA - - DNA genes are copied to ribonucleic acid
- guides construction of cell parts and proteins
- helps construct proteins based on genetic instructions
- proteins constructed on ribosomes, cellular workbenches of specialized RNA called ribosomal
RNA
prokaryotic cells - - relatively simple internal structure
- generally less than 5 micrometers in diameter
, - unicellular
- make up two domains: Archaea and Bacteria
- specialized cytoplasmic structures (nucleoid and plasmids)
nucleoid - distinct region that contains single circular chromosome that consists of long, piled
strand of DNA
plasmids - small rings of DNA
prokaryotic cells' distinctive surface features - - nearly all surrounded by cell wall
cell wall - - provides protection and helps cell maintain its shape
- shapes may be rod-like, spiral, or spherical
gram positive - - thick peptidoglycan layer
- layer retains dye crystal violet
- also has teichoic acid
gram negative - - thin layer of peptidoglycan in periplasmic space
- contains thick lipopolysaccharide layer, which prevents crystal violet color to be retained by
cell
- cells can be seen by counterstain Safranin red dye
Bacillus anthrax - - gram postive bacteria
- vegetative cells showing retention of crystal violet
- can produce spores that survive about 48 years or more
- in US mail "2001 Anthrax scare"
pili (singular pilus) - - surface proteins (pilin) that project from cell walls of many bacteria
- two types of pili: attachment and sex
attachment pili - help bacteria adhere to surfaces
sex pili - form connections between adjacent bacteria that allow them to transfer plasmids
flagella (singular flagellum) - - some bacteria and archaea possess this
- extend from cell surface
- rotate and propel cell through fluid environment
- flagellin protein is principle component of bacteria flagella
Eukaryotic cells make up bodies of organisms in domain Eukarya - - contain organelles
membrane-enclosed structures specialized for a particular function
- organelles contribute to complexity of eukaryotic cells
extracellular matrix - function: surround cells, providing biochemical and structural support
- mostly absent in prokaryotes
