BIO 272 Exam 1 Questions and Answers
Why take Bio 272? - Correct Answers -Because everything alive is made of cells
(smallest unit of life)!
Common features for the properties of life - Correct Answers -1. Utilize and transform
energy and matter
2. Generate and maintain ordered structures
3. Homeostasis/Regulation
4. Stimulus response
5. Reproduction
6. Growth and development
Utilize and transform energy and matter - Correct Answers -Organisms exploit non-
biological energy sources (ex light) and/or energy-rich organic compounds (ex sugars)
to break and rearrange covalent bonds in organic compounds + to perform various
processes.
Generate and maintain ordered structures - Correct Answers -Living organisms
increase order within themselves by using energy obtained from their environment
Homeostasis - Correct Answers -Organisms use energy to maintain stable internal
conditions (ex pH, salt concentrations, temperature)
Stimulus response - Correct Answers -Organisms respond to stimulus and adapt to
survive based on environmental changes
Reproduction - Correct Answers -Everything an organism does is to harvest enough
energy and generate enough biological molecules to reproduce themselves
Growth and development - Correct Answers -Maximizing ability to reproduce through
these processes
Cell theory - Correct Answers -All living organisms are derived from earlier living
organisms
Robert Hooke (1665) - Correct Answers -first to observe "small chambers" in cork and
call them cells.
,ion channels (gated channels) - Correct Answers -- Channels that open or close
depending on the presence or abscence of an electrical, chemical, or physical stimulus.
- Transport ions through membrane
- Golilocks Principal: placement of electrostatic groups in selectivity filter must perfectly
fit the size of the ion being transported
Signal sequence hypothesis - Correct Answers -- protein targeting information is
contained within short polypeptide sequences, and these are necessary and sufficient to
confer protein targeting to distinct cellular organelles (e.g. ER, mitochondria,
chloroplast, peroxisome, nucleus)
- Often, but not always, these targeting sequences are proteolytically cleaved from
proteins after they have reached their target destinations
Signal sequence - Correct Answers -amino-terminal stretch of 15-20 amino acids that
form a hydrophobic α-helix targets proteins to ER
Van Leeuwenhoek (1674) - Correct Answers -1st person to see microscopic organisms
using a microscope "animalcules" or protozoa in pond water
Mattias Schleiden and Theodor Schwann - Correct Answers -formulated cell theory
(1838) (from plants and animals new cells form from dividing nuclei)
Rudolf Virchow (1855) - Correct Answers -All cells come from pre-existing cells
Louis Pasteur (1860s) - Correct Answers -Disproved the spontaneous generation
hypothesis: By sterilizing cultures and keeping them isolated from the open air, Pasteur
found that contamination of the media only occurred upon exposure to the outside
environment
Unity and diversity of cells - Correct Answers -For all organisms it is true that
- DNA is the genetic molecules and encodes genetic information
- Replication of this DNA allows propagation of this genetic information to future
generations
- DNA is transcribed into RNA intermediates
- RNA is translated into functional protein enzymes
Defining features of prokaryotes - Correct Answers -- Lack a nucleus
- Smaller in size (about 1-10 um)
- Lack of organelles (few or none)
- Circular DNA in cytoplasm
- DNA, RNA, and proteins are all mixed together in the cytoplasm
- Mainly unicellular
- Simple cytoskeleton; no endo/exocytosis
- Divides by simple binary fission
- Typically spherical, rodlike, or spiral shaped
- Often surrounded by cell wall and capsule
, - Can exploit diverse range of habitats (extremeophiles, aerobic/anaerobic etc.)
- Evolved to catabolize almost anything
- Ex. bacteria, archae, cyanobacteria
Defining features of eukaryotes - Correct Answers -- Nucleus
- Larger size (about 10-100 um)
- Lots of subcellular organelles that are membrane-bound
-Unicellular and multicellular
- Linear DNA called chromosomes in nucleus
- DNA and RNA transcription limited to inside of nucleus, RNA translation into proteins
limited to cytoplasm
- Elaborate cytoskeleton, both endo/exocytosis
- Divides my mitosis and meiosis
- Ex. protists, fungi, plants, animals
Origins of eukaryotes - Correct Answers -Thought to have originated when one
"predatory"/archaebacterial prokaryotic cell engulfed a gram-negative prokaryote (called
endosymbiosis)
Internalization of prokaryotes - Correct Answers -Also though to have given rise to
mitochondria in all eukaryotes and chloroplasts in photosynthetic eukaryotes
Multicellularity - Correct Answers -Differentiated cells have the SAME DNA.... but
different genes are selectively turned on or off
Cytosol - Correct Answers -The soluble portion of the cytoplasm, which includes
molecules and small particles, such as ribosomes, but not the organelles covered with
membranes.
Nucleus - Correct Answers -- 10 um in diameter, most prominent organelle in eukaryotic
cells
- contains genomic DNA in a series of linear DNA molecules called chromosomes
- Nuclear envelope membranes separate the nucleoplasm from the cytoplasm
- The nucear envelope is continuous with the endoplasmic reticulum
- Transport of macromolecules between cytoplasm and nucleoplasm accomplished
through nuclear pore complexes
Mitochondria - Correct Answers -- Double membrane due to endosymbiotic origins
- Retain circular DNA genome left over from the gram-negative prokaryote
- Replicate by division within the cytoplasm of the eukaryotic cell
- Outer membrane is permeable, inner membrane is not
- Inner membrane forms cristae that penetrate into the internal mitochondrial lumen
(mitochondrial matrix)
- The cristae contain most of hte cellular components for cellular respiration
Why take Bio 272? - Correct Answers -Because everything alive is made of cells
(smallest unit of life)!
Common features for the properties of life - Correct Answers -1. Utilize and transform
energy and matter
2. Generate and maintain ordered structures
3. Homeostasis/Regulation
4. Stimulus response
5. Reproduction
6. Growth and development
Utilize and transform energy and matter - Correct Answers -Organisms exploit non-
biological energy sources (ex light) and/or energy-rich organic compounds (ex sugars)
to break and rearrange covalent bonds in organic compounds + to perform various
processes.
Generate and maintain ordered structures - Correct Answers -Living organisms
increase order within themselves by using energy obtained from their environment
Homeostasis - Correct Answers -Organisms use energy to maintain stable internal
conditions (ex pH, salt concentrations, temperature)
Stimulus response - Correct Answers -Organisms respond to stimulus and adapt to
survive based on environmental changes
Reproduction - Correct Answers -Everything an organism does is to harvest enough
energy and generate enough biological molecules to reproduce themselves
Growth and development - Correct Answers -Maximizing ability to reproduce through
these processes
Cell theory - Correct Answers -All living organisms are derived from earlier living
organisms
Robert Hooke (1665) - Correct Answers -first to observe "small chambers" in cork and
call them cells.
,ion channels (gated channels) - Correct Answers -- Channels that open or close
depending on the presence or abscence of an electrical, chemical, or physical stimulus.
- Transport ions through membrane
- Golilocks Principal: placement of electrostatic groups in selectivity filter must perfectly
fit the size of the ion being transported
Signal sequence hypothesis - Correct Answers -- protein targeting information is
contained within short polypeptide sequences, and these are necessary and sufficient to
confer protein targeting to distinct cellular organelles (e.g. ER, mitochondria,
chloroplast, peroxisome, nucleus)
- Often, but not always, these targeting sequences are proteolytically cleaved from
proteins after they have reached their target destinations
Signal sequence - Correct Answers -amino-terminal stretch of 15-20 amino acids that
form a hydrophobic α-helix targets proteins to ER
Van Leeuwenhoek (1674) - Correct Answers -1st person to see microscopic organisms
using a microscope "animalcules" or protozoa in pond water
Mattias Schleiden and Theodor Schwann - Correct Answers -formulated cell theory
(1838) (from plants and animals new cells form from dividing nuclei)
Rudolf Virchow (1855) - Correct Answers -All cells come from pre-existing cells
Louis Pasteur (1860s) - Correct Answers -Disproved the spontaneous generation
hypothesis: By sterilizing cultures and keeping them isolated from the open air, Pasteur
found that contamination of the media only occurred upon exposure to the outside
environment
Unity and diversity of cells - Correct Answers -For all organisms it is true that
- DNA is the genetic molecules and encodes genetic information
- Replication of this DNA allows propagation of this genetic information to future
generations
- DNA is transcribed into RNA intermediates
- RNA is translated into functional protein enzymes
Defining features of prokaryotes - Correct Answers -- Lack a nucleus
- Smaller in size (about 1-10 um)
- Lack of organelles (few or none)
- Circular DNA in cytoplasm
- DNA, RNA, and proteins are all mixed together in the cytoplasm
- Mainly unicellular
- Simple cytoskeleton; no endo/exocytosis
- Divides by simple binary fission
- Typically spherical, rodlike, or spiral shaped
- Often surrounded by cell wall and capsule
, - Can exploit diverse range of habitats (extremeophiles, aerobic/anaerobic etc.)
- Evolved to catabolize almost anything
- Ex. bacteria, archae, cyanobacteria
Defining features of eukaryotes - Correct Answers -- Nucleus
- Larger size (about 10-100 um)
- Lots of subcellular organelles that are membrane-bound
-Unicellular and multicellular
- Linear DNA called chromosomes in nucleus
- DNA and RNA transcription limited to inside of nucleus, RNA translation into proteins
limited to cytoplasm
- Elaborate cytoskeleton, both endo/exocytosis
- Divides my mitosis and meiosis
- Ex. protists, fungi, plants, animals
Origins of eukaryotes - Correct Answers -Thought to have originated when one
"predatory"/archaebacterial prokaryotic cell engulfed a gram-negative prokaryote (called
endosymbiosis)
Internalization of prokaryotes - Correct Answers -Also though to have given rise to
mitochondria in all eukaryotes and chloroplasts in photosynthetic eukaryotes
Multicellularity - Correct Answers -Differentiated cells have the SAME DNA.... but
different genes are selectively turned on or off
Cytosol - Correct Answers -The soluble portion of the cytoplasm, which includes
molecules and small particles, such as ribosomes, but not the organelles covered with
membranes.
Nucleus - Correct Answers -- 10 um in diameter, most prominent organelle in eukaryotic
cells
- contains genomic DNA in a series of linear DNA molecules called chromosomes
- Nuclear envelope membranes separate the nucleoplasm from the cytoplasm
- The nucear envelope is continuous with the endoplasmic reticulum
- Transport of macromolecules between cytoplasm and nucleoplasm accomplished
through nuclear pore complexes
Mitochondria - Correct Answers -- Double membrane due to endosymbiotic origins
- Retain circular DNA genome left over from the gram-negative prokaryote
- Replicate by division within the cytoplasm of the eukaryotic cell
- Outer membrane is permeable, inner membrane is not
- Inner membrane forms cristae that penetrate into the internal mitochondrial lumen
(mitochondrial matrix)
- The cristae contain most of hte cellular components for cellular respiration
