MICRO Exam 1 (Ch 3, 4, 5)
Prokaryotic ribosomes (70S) are composed of two subunits: the ______ (small subunit) and the ______(large subunit), each of which are composed of protein and rRNA components.
-30S -50S
Eukaryotic cells contain ______ ribosomes in the rough endoplasmic reticulum (membrane bound-ribosomes) and cytoplasm (free ribosomes). They contain _____ ribosomes in mitochondria and chloroplasts.
-80S -70S
Prokaryotic cells that are rod-shaped are called _____________.
bacilli
-located in nucleoid region One double-stranded DNA molecule Frequently circular and super-coiled Contains all genes required for survival and replication
bacterial chromosome
peripheral proteins are _____ to the membrane
bound
In prokaryotic cells, the ______ includes a plasma membrane and usually a cell wall.
cell envelope
Prokaryotic cells of the same species typically share a similar ______ and _____.
cell morphology and cellular arrangement.
Although cells were first observed in the 1660s by Robert Hooke, ________ was not well accepted for another 200 years. The work of scientists such as Schleiden, Schwann, Remak, and Virchow contributed to its acceptance.
cell theory
In prokaryotic cells, the ______ provides some protection against changes in osmotic pressure, allowing it to maintain its shape longer.
cell wall
Most prokaryotic cells have a _______ that helps the organism maintain cellular morphology and protects it against changes in osmotic pressure.
cell wall
moves solutes across a membrane
diffusion
Eukaryotic cells have evolved an ______ system, containing membrane-bound organelles involved in transport. These include vesicles, the endoplasmic reticulum, and the Golgi apparatus.
endomembrane
-Specialized "resting/hibernating" cells Allow survival if environment poor - Last-ditch survival mechanism! -Resistant to desiccation, heat, chemicals
endospores
John Snow is known as the Father of _____________.
epidemiology
Greek for true nucleus
eukaryote
-paired chromosomes in nucleus -many membrane-bound organelles -cell walls absent or simple structure -complex division process
eukaryotes
-Short, circular double-stranded DNA -5-100 non-essential genes that generally provide a selective advantage -Antibiotic resistance, extra enzymes, etc. -Inter-bacterial transfer often via pilus
extra-chromosomal plasmids
Cells of fungi, algae, plants, and some protists have a cell wall, whereas cells of animals and some protozoans have a sticky __________ that provides structural support and mediates cellular signaling.
extracellular matrix
moves solutes down a concentration gradient through a membrane protein.
facilitated diffusion
True or false: Bacteria have 80S ribosomes each composed of a 60S large subunit and a 40S small subunit.
false
True or false: Exposure to air is necessary for microbial growth.
false
The miasma theory of disease was widely accepted until the 19th century, when it was replaced by the _______ thanks to the work of Semmelweis, Snow, Pasteur, Lister, and Koch, and others.
germ theory of disease
Endospores can __________, transforming back into vegetative cells when conditions improve.
germinate
return to vegetative state/ growth state
germination
Peroxisomes typically produce _____________, a harsh chemical that helps break down molecules.
hydrogen peroxide
Water particles move out of the cell. Cell membrane shrinks and detaches from the cell wall (plasmolysis).
hypertonic solution
A solution that has a lower solute concentration than another solution. Water particles will move into the cell, causing the cell to expand and eventually lyse.
hypotonic solution
Some prokaryotic cells have ________ that store nutrients or chemicals for other uses.
inclusions
one or more protein segments embedded into the membrane would be called ______
integral
Prokaryotic cell walls may be composed of ________ (bacteria) or ___________ (archaea).
-peptidoglycan -pseudopeptidoglycan
Bacterial membranes are composed of ________ with _______or _______ proteins. The fatty acid components of these _________ are ester-linked and are often used to identify specific types of bacteria. The proteins serve a variety of functions, including transport, cell-to-cell communication, and sensing environmental conditions. Archaeal membranes are distinct in that they are composed of fatty acids that are ether-linked to phospholipids.
-phospholipids -integral -peripheral -phospholipids
Some prokaryotic cells are able to form endospores through _______ to survive in a dormant state when conditions are unfavorable.
-sporolation
Gram-positive bacterial cells are characterized by a (thick/thin) peptidoglycan layer, whereas gram-negative bacterial cells are characterized by a (thick/thin) peptidoglycan layer surrounded by an outer membrane.
-thick -thin
Prokaryotic ribosomes that are found in the cytoplasm have a size of _____.
70S
17. Which of the following is not composed of microtubules? a. desmosomes b. centrioles c. eukaryotic flagella d. eukaryotic cilia
A
9. Which of the following cell wall components is unique to gram-negative cells? a. lipopolysaccharide b. teichoic acid c. mycolic acid d. peptidoglycan
A
What is the primary difference between a eukaryote and a prokaryote?
A eukaryote has a true membrane bound nucleus, where as the prokaryote does not
13. Which type of cytoskeletal fiber is important in the formation of the nuclear lamina? a. microfilaments b. intermediate filaments c. microtubules d. fibronectin
B
16. Which type of nutrient uptake involves the engulfment of small dissolved molecules into vesicles? a. active transport b. pinocytosis c. receptor-mediated endocytosis d. facilitated diffusion
B
4. Which of the following individuals did not contribute to the establishment of cell theory? A. Girolamo Fracastoro B. Matthias Schleiden C. Robert Remak D. Robert Hooke
B
6. Which of the following developed a set of postulates for determining whether a particular disease is caused by a particular pathogen? a. John Snow b. Robert Koch c. Joseph Lister d. Louis Pasteur
B
1. Which of the following individuals argued in favor of the theory of spontaneous generation? A. Francesco Redi b. Louis Pasteur c. John Needham d. Lazzaro Spallanzan
C
14. Sugar groups may be added to proteins in which of the following? a. smooth endoplasmic reticulum b. rough endoplasmic reticulum c. Golgi apparatus d. lysosome
C
5. Whose proposal of the endosymbiotic theory of mitochondrial and chloroplast origin was ultimately accepted by the greater scientific community? a. Rudolf Virchow b. Ignaz Semmelweis c. Lynn Margulis d. Theodor Schwann
C
7. Which of the following terms refers to a prokaryotic cell that is comma shaped? a. coccus b. coccobacilli c. vibrio d. spirillum
C
8. Which bacterial structures are important for adherence to surfaces? (Select all that apply.) a. endospores b. cell walls c. fimbriae d. capsules e. flagella
C
_______ are microtubule-organizing centers important in the formation of the mitotic spindle in mitosis.
Centrosomes
Eukaryotic flagella are structurally distinct from prokaryotic flagella but serve a similar purpose (locomotion). ______ are structurally similar to eukaryotic flagella, but shorter; they may be used for locomotion, feeding, or movement of extracellular particles.
Cilia
What are 2 examples of spore formers?
Clostridium and Bacillus
10. Which of the following terms refers to a bacterial cell having a single tuft of flagella at one end? a. monotrichous b. amphitrichous c. peritrichous d. lophotrichous
D
11. Bacterial cell walls are primarily composed of which of the following? a. phospholipid b. protein c. carbohydrate d. peptidoglycan
D
12. Which of the following organelles is not part of the endomembrane system? a. endoplasmic reticulum b. Golgi apparatus c. lysosome d. peroxisome
D
15. Which of the following structures of a eukaryotic cell is not likely derived from endosymbiotic bacterium? a. mitochondrial DNA b. mitochondrial ribosomes c. inner membrane d. outer membrane
D
2. Which of the following individuals is credited for definitively refuting the theory of spontaneous generation using broth in swan-neck flask? A. Aristotle B. Jan Baptista van Helmont C. John Needham D. Louis Pasteur
D
3. Which of the following scientists experimented with raw meat, maggots, and flies in an attempt to disprove the theory of spontaneous generation? A. Aristotle B. Lazzaro Spallanzani C. Antonie van Leeuwenhoek D. Francesco Redi
D
Eukaryotic cells are defined by the presence of a nucleus containing the _______ and bound by a nuclear membrane (or nuclear envelope) composed of two lipid bilayers that regulate transport of materials into and out of the nucleus through nuclear pores.
DNA genome
states that mitochondria and chloroplasts, organelles found in many types of organisms, have their origins in bacteria. Significant structural and genetic information support this theory.
Endosymbiotic theory
________ is credited with conclusively disproving the theory of spontaneous generation with his famous swan-neck flask experiment. He subsequently proposed that "life only comes from life."
Louis Pasteur
________ are the site of cellular respiration. They have two membranes: an outer membrane and an inner membrane with cristae. The mitochondrial matrix, within the inner membrane, contains the mitochondrial DNA, 70S ribosomes, and metabolic enzymes.
Mitochondria
Prokaryotic cells differ from eukaryotic cells in that their genetic material is contained in a ________rather than a membrane-bound nucleus. In addition, prokaryotic cells generally lack membrane-bound organelles.
Nucleoid
_______ contain digestive enzymes that break down small particles ingested by endocytosis, large particles or cells ingested by phagocytosis, and damaged intracellular components.
lysosomes
The ____________ theory states that disease may originate from proximity to decomposing matter and is not due to person-to-person contact.
miasma
Some prokaryotic cells use one or more flagella to move through water. __________ bacteria, which have numerous flagella, use runs and tumbles to move purposefully in the direction of a chemical attractant.
Peritrichous
The scientist who first described cells was _____________.
Robert Hooke
a condensed area of DNA found within prokaryotic cells. Because of the density of the area, it does not readily stain and appears lighter in color when viewed with a transmission electron microscope.
nucleoid region
The ________, located in the nucleus of eukaryotic cells, is the site of ribosomal synthesis and the first stages of ribosome assembly.
nucleolus
moves water across a membrane when a solute cannot move
osmosis
-Does NOT require energy -Move with the concentration gradient (high to low)
passive Transport
a phospholipid bilayer with a variety of embedded proteins that perform various functions for the cell. Note the presence of glycoproteins and glycolipids, whose carbohydrate components extend out from the surface of the cell. The abundance and arrangement of these proteins and lipids can vary greatly between species.
plasma membrane
Outside of the nucleoid, prokaryotic cells may contain extrachromosomal DNA in ______.
plasmids
Greek for pre-nucleus
prokaryote
-circular genome, often have plasmids -no organelles -relatively complex cell wall structure -simple division process
prokaryotes
A typical ______ cell contains a cell membrane, chromosomal DNA that is concentrated in a nucleoid, ribosomes, and a cell wall. Some of these cells may also possess flagella, pili, fimbriae, and capsules.
prokaryotic
-80% water -Contains ions and organic molecules -No cytoskeleton components
prokaryotic cytoplasm
what are the 2 types of diffusion?
simple and facilitated
moves solutes down a concentration gradient directly across the phospholipid bilayer.
simple diffusion
The assertion that "life only comes from life" was stated by Louis Pasteur in regard to his experiments that definitively refuted the theory of ___________.
spontaneous generation
The theory of _________ states that life arose from nonliving matter. It was a long-held belief dating back to Aristotle and the ancient Greeks.
spontaneous generation
endospore formation
sporulation
The plasma membrane of eukaryotic cells is structurally similar to that found in prokaryotic cells, and membrane components move according to the fluid mosaic model. However, eukaryotic membranes contain _______, which alter membrane fluidity, as well as glycoproteins and glycolipids, which help the cell recognize other cells and infectious particles.
sterols
_______ terms refer to the outside solute concentration with respect to the inside solute concentration.
tonicity
proteins that extend from one side of the membrane to the other.
transmembrane
True or false: Mitochondria in eukaryotic cells contain ribosomes that are structurally similar to those found in prokaryotic cells
true
The type of inclusion containing polymerized inorganic phosphate is called _____________.
volutin
The ___________ plays a role in lipid biosynthesis, carbohydrate metabolism, and detoxification of toxic compounds. The ___________ contains membrane-bound 80S ribosomes that synthesize proteins destined for the cell membrane
-Smooth Endoplasmic Reticulum -rough endoplasmic reticulum
Sporulation begins following ________. The forespore becomes surrounded by a double layer of membrane, a cortex, and a protein spore coat, before being released as a mature endospore upon disintegration of the mother cell.
-asymmetric cell division
Some prokaryotic cells produce glycocalyx coatings, such as ______ and ______, that aid in attachment to surfaces and/or evasion of the host immune system.
-capsules -slime layers
In cells that lack a cell wall, changes in osmotic pressure can lead to ______ in hypertonic environments or _______ in hypotonic environments.
-crenation -cell lysis
Eukaryotic cell morphologies vary greatly and may be maintained by various structures, including the _______, the _______, and/or the _______.
-cytoskeleton -cell membrane -cell wall
In addition to active transport and passive transport, eukaryotic cell membranes can take material into the cell via _______, or expel matter from the cell via ______.
-endocytosis -exocytosis
Some prokaryotic cells have______ or ______, filamentous appendages that aid in attachment to surfaces. Pili are also used in the transfer of genetic material between cells.
-fimbriae -pili
The cytoskeleton, composed of ______, _______, and _________ provides structural support in eukaryotic cells and serves as a network for transport of intracellular materials.
-microfilaments - intermediate filaments -microtubules
Experimentation by ________ in the 17th century presented the first significant evidence refuting spontaneous generation by showing that flies must have access to meat for maggots to develop on the meat. Prominent scientists designed experiments and argued both in support of (John Needham) and against (Lazzaro Spallanzani) spontaneous generation.
Francesco Redi
The ________processes proteins and lipids, typically through the addition of sugar molecules, producing glycoproteins or glycolipids, components of the plasma membrane that are used in cell-to-cell communication.
Golgi apparatus
A solution that has a higher solute concentration than another solution. Water particles will move out of the cell causing crenation.
Hypertonic solution
A solution that has the same solute concentration as another solution. There is no net movement of water particles, and the overall concentration on both sides of the cell membrane remains constant.
Isotonic solution
No net movement of water particles. Cell membrane is attached to the cell wall.
Isotonic solution
Microfilaments are composed of _____________ monomers.
actin
-Requires energy -Move against the concentration gradient (low to high) -Moves solute across a membrane -needs ATP and requires a pump
active transport
Some molecules can move across the bacterial membrane by simple diffusion, but most large molecules must be ________ through membrane structures using cellular energy.
actively transported