Biology CH1 - The Cell

What did Robert Hooke do?

He assembled a microscope. To test it he used a piece of cork. He saw honeycomb like structures and compared them to small rooms, called cells. (1.1)

What did Robert Hooke didn't see?

Since the piece of cork he viewed contained nonliving cells, he didn't see the cell's nuclei, organelles, or cell membranes. (1.1)

Who was the first one to view living cells under microscope?

Anton van Leeuwenhoek (1.1)

What did Rudolf Virchow demonstrate?

He demonstrated that diseased cells could arise from normal cells in normal tissues (1.1)

What are the four fundamental tenets of the cell theory?

1) All living things are composed of cells2) The cell is the basic unit of life3) Cells arise only from preexisting cells4) Cells carry genetic information in the forms of DNA. This genetic material is passed on from parent to daughter cell. (1.1)

What are viruses?

small structures that contain genetic material, but are unable to reproduce on their own. (1.1)

Do viruses meet 4 tenants of fundamental cell theory? Reasoning?

No they violate 3rd and 4th tenants of the cell theory.Reason: virions reproduce by invading other organisms. Also they can use RNA as their genetic material. (1.1)

What is the difference between Eukaryotes and Prokaryotes?

Prokaryotic - single celled, don't contain nucleusEukaryotic - can be unicellular or multicellular, contain true nucleus enclosed in membrane. (1.2)

What does cell membrane enclose?

encloses a semifluid cytosol in which organelles are suspended (1.2)

What does bounding organelles to membrane allow?

Compartmentalization (1.2)

What do membranes of Eukaryotic cells consist of?

phospholipid bilayer (1.2)

What makes a phospholipid membrane unique?

out - hydrophilicin - hydrophobic, creates highly selective barrier (1.2)

What is the function of cytosol?

allows for the diffusion of molecules throughout the cell (1.2)

What is enclosed within nucleus?

genetic material encoded in DNA, DNA is organized into chromosomes (1.2)

How do eukaryotic cells reproduce?

mitosis, allowing for the formation of two identical daughter cells (1.2)

What is the control center of the cell?

nucleus (1.2)

What does the nucleus contain?

all of the genetic material necessary for replication of the cell (1.2)

What is nuclear membrane?

surrounds nucleus, a double membrane that maintains a nuclear environment separate and distinct from the cytoplasm (1.2)

What is the function of nuclear pores?

Nuclear pores in membrane allow selective two way exchange of material between the cytoplasm and the nucleus (1.2)

How do you call coding regions in the DNA?

genes (1.2)

What is the process of linear DNA wounding up?

linear DNA ==> histones (organizing proteins)histones ==> chromosomes (linear strands) (1.2)

What does location of DNA in the nucleus permit?

It permits compartmentalization of DNA transcription separate from RNA translation. (1.2)

What is Nucleolus?

place where rRNA is synthesized. Takes 25% of nucleus. Darker spot in nucleus. (1.2)

What is the common name for mitochondria?

powerplants of the cell, in reference to their important metabolic functions (1.2)

How many layers does mitochondria have? Name them.

It has 2 layers:1) inner membrane2) outer membrane (1.2)

What is the purpose of the outer membrane in Mitochondria?

serves as barrier between cytosol and inner environment of the mitochondrion (1.2)

How do you call infoldings in the inner membrane of mitochondria?

cristae (1.2)

What does cristae contain?

contains molecules and enzymes of the electron transport chain (1.2)

Why are cristae folded?

they increase the surface area for more electron transport chain enzymes (1.2)

How do you call space between in & out membranes of mitochondria?

intermembrane space (1.2)

How do you call space inside inner membrane of mitochondria?

matrix (1.2)

What does pumping of protons from matrix to intermembrane result?

proton motive force, these protons flow through ATP synthase to generate ATP during oxidative phosphorylation. (1.2)

What does semi-autonomous mean?

Part of the cell which contains its own genes and replicates independently of the nucleus via binary fission. (1.2)

What is cytoplasmic inheritance?

transmission of genetic material independent of the nucleus (1.2)

How did mitochondria originate?

engulfing of an aerobic prokaryote by an anaerobic prokaryote resulted in a symbiotic relationship (1.2)

What is apoptosis? Describe.

programmed cell death.mitochondria releases enzymes from the electron transport chain. (1.2)

What is a lysosome?

membrane-bound structure containing hydrolytic enzymes that are capable of breaking down many different substrates, including substances ingested by endocytosis and cellular waste products (1.2)

Lysosomes often work together with what?

endosomes (1.2)

What are endosomes?

organelles that transport, package, and sort cell material traveling to and from the membrane (1.2)

where do endosomes transport things?

transport to trans-golgi, to cell membrane, or to lysosomal pathway to degradation (1.2)

How do lysosomes prevent damage to the cell?

Lysosomal membrane sequester enzymes to prevent cell damage (1.2)

What is autolysis?

release of enzymes (1.2)

What happens when lysosomes release enzymes?

like mitochondria, lysosomes release hydrolytic enzymes, resulting in apoptosis. Leading directly to damage of cellular components. (1.2)

What is ER?

A series of interconnected membranes that are actually contiguous with nuclear envelope. (1.2)

Describe double membranes of ER?

folded into numerous invaginations, creating complex structures with a central lumen. (1.2)

What is rough ER? (Structure & Function)

studded with ribosomes, which permit the translation of proteins destined for secretion directly into lumen (1.2)

What is smooth ER? (Structure & Function)

lack ribosomesutilized primarily for lipid synthesis (like phospholipids) and detoxification of certain drugs and poisons. (1.2)

How is ER & Golgi Apparatus related?

SER also transports proteins from the RER to the Golgi apparatus (1.2)

Describe structure of Golgi apparatus?

consists of stacked membrane-bound sacs (1.2)

How are materials transferred from ER to Golgi?

in vesicles (1.2)

What happens inside of Golgi?

cellular products may be modified by addition of groups like carbohydrates, phosphates, and sulfates (1.2)

What is signal sequences process?

direct the delivery of the product to a specific cellular location. (1.2)

What happens to cellular products after modification in Golgi?

After modification, cellular products are repackaged in vesicles, which are then directed to the correct cellular location. (1.2)

What is exocytosis?

secretory vesicle merges with the cell membrane and its contents are released. (1.2)

What do peroxisomes contain?

hydrogen peroxide (1.2)

What is the primary function of peroxisomes?

breakdown of very long chain fatty acids via beta-oxidation. (1.2)

What are other functions of peroxisomes beside beta-oxidation?

participate in synthesis of phospholipids contain some of the enzymes involved in the pentose phosphate pathway (1.2)

What is the cytoskeleton?

provides structure to the cell and helps it to maintain its shape.provides a conduit for the transport of materials around the cell. (1.2)

What are three components of cytoskeleton?

1. microfilaments2. microtubules3. intermediate filaments (1.2)

What are microfilaments made of?

microfilaments are made up of solid polymerized rods of actin. (1.2)

How do actin filaments provide support?

They are organized into bundles and networks and are resistant to both compression and fracture. (1.2)

What happens when actin uses ATP?

This relationship allows to generate force movement by interacting with myosin. Ex: Muscle contraction (1.2)

What is cytokinesis?

division of materials between daughter cells. (1.2)

What do microfilaments do during mitosis?

They form cleavage furrow, which organize as a ring at the site of division between the two new daughter cell. (1.2)

What happens when the actin filaments in the cleavage furrow contract?

ring becomes smaller, pinching off the connection between two daughter cells. (1.2)

What are microtubules made of?

hollow polymers of tubulin (1.2)

Microtubules provide primary pathway along which motor proteins?

kinesin and dynein, carry vesicles (1.2)

Which motile structure are made of microtubules?

cilia and flagella (1.2)

What is a cilia? Give an example.

projections from a cell that are primarily involved in the movement of materials along the surface of the cell. Ex: cilia line up respiratory tract and are involved in the movement of mucus. (1.2)

What is Flagella? Give example.

structure involved in the movement of the cell itself.Ex: movement of sperm cell (1.2)

Describe the structure of cilia and flagella. Is it seen anywhere else?

nine microtubules form a ring doublet two microtubules in centerknown as 9+2 structureseen only in eukaryotic organelles of motility (1.2)

Where is centriole found in the cell?

in centrosome (1.2)

What is the structure of centriole?

9 triplets of microtubules (1.2)

What do the centrioles do during mitosis?

centrioles migrate to opposite poles of the dividing cell and organize the mitotic spindle (1.2)

What do microtubules emanating from the centrioles do?

attach to the chromosomes via kinetochores complexes and exert forces on the sister chromatids, pulling them apart. (1.2)

What are intermediate filaments made of?

diverse groups of filamentous proteins:*keratin*desmin*vemintin*lamins(1.2)

What do intermediate filaments do?

*involved in cell-cell adhesion or maintenance of the overall integrity of cytoskeleton*help anchor other organelles, including nucleus. (1.2)

How do intermediate filaments increase structural rigidity?

They are able to withstand tremendous amount of tension (1.2)

What is identity of intermediate filaments in each cell?

The identity of int. fil. varies depending on the cell type and tissue type. (1.2)

What is a unique characteristic of eukaryotic cells?

formation of tissues with division of labor (1.2)

What are the four types of tissues?

epithelial, connective, muscle, nervous (1.2)

What are epithelial tissues?

cover body and line its cavities, providing for protection against pathogen invasion and desiccation. (1.2)

What do epithelial cells do in certain organs?

involved in absorption, secretion, and desiccation. (1.2)

What do epithelial cells do to remain as one cohesive unit?

they are tightly joined to each other and to an underlying layer of connective tissue known as the basement membrane. (1.2)

What functions do epithelial cells serve in organs?

in most organs epithelial cells constitute the parenchyma or the functional parts of the organ. (1.2)

What does polarized epithelial cells mean?

one side faces the lumen or the outside world, while the other side interacts with underlying blood vessels and structural cells. (1.2)

How are epithelial cells classified?

based on layers and shape (1.2)

What are layer classifications for epithelial cells?

Simple epithelia - 1 layer of cellsStratified epithelia - multiple layerspseudostratified epithelia - have multiple layers due to difference in cell height but are in reality, only one layer (1.2)

What are shape classifications for epithelial cells?

cuboidal - cube shapecolumnar - long and thinsquamous - flat and scale like (1.2)

What are connective tissues?

supports the body and provides framework for the epithelial cells to carry out their functions. (1.2)

Connective tissues are main contributors of organ in what?

stroma or support structure (1.2)

What are example of connective tissue?

Bone, cartilage, tendons, ligaments, adipose tissue, and blood. (1.2)

Most cells in connective tissue and secrete which materials? Later they form what?

produce collagen and elastin to form extracellular matrix (1.2)

What are prokaryotes?

simples of all organisms and include all bacteria. (1.3)

Describe organelles of prokaryotes.

don't contain any membrane bound organelles (1.3)

Describe genetic material of prokaryotes

Organized into a single circular molecule of DNA concentrated in an area of the cell called nucleoid region. (1.3)

What are 3 Domains into which life is classified?

1) Archaea2)Bacteria3) Eukarya (1.3)

What are archaea?

single-celled organisms that are visually similar to bacteria, but contain genes and several metabolic pathways that are more similar to eukaryotes than to bacteria (1.3)

What are extremophiles? And why archaea was called this historically?

they were most commonly isolated from harsh environments with extremely high temperatures, high salinity, or no light. (1.3)

How do you classify Archaea that use alternative sources of energy?

photosynthetic - generate energy from lightchemosynthetic - generate energy from inorganic compounds including sulfur and nitrogen based compounds such as ammonia (1.3)

What are similarities between Archaea and Eukaryotes?

*share common origin*both start translation with methionine*contain similar RNA polymerases*associate their DNA with histones (1.3)

How are Archaea different from Eukaryotes?

*Archaea have singular circular chromosome*Archaea divide by binary fission or budding*Archaea share a similar overall structure to bacteria (1.3)

Many Archaea are resistive to what?

resistant to many antibiotics (1.3)

What do all bacteria have in common?

*cell membrane *cytoplasm*flagella or fimbriae (similar to cilia) (1.3)

Why is it difficult to develop medicine which only targets bacteria?

because bacteria and eukaryotes often share analogous structures (1.3)

What can antibacterial medicine target?

*bacterial and eukaryotic flagella are different enough, which helps development of antibacterial vaccines*Many antibiotics target the bacterial ribosomes, which are smaller than the ones of eukaryotes (1.3)

By how much do bacterial cells outnumber human cells?

10:1 (1.3)

What are mutualistic symbiotes? List examples:

*both humans and bacteria benefit from the relationshipEx: bacteria in human gut which:*makes vitamin K and biotin*prevents the overgrowth of harmful bacteria (1.3)

What are pathogens or parasites?

they provide no advantage or benefit to the host, but rather cause disease. (1.3)

Where can pathogenic bacteria live? List types:

They live intracellularly or extracellularlychlamydia traehomatis - common sex transmitted infection, lives inside the cell of reproductive tractclostridium tetani - the cause of tetanus, lives outside of cells and produces toxins that enter the bloodstream. (1.3)

What are the 3 shapes of bacteria? Give examples:

cocci - spherical bacteriaex: streptococcus pyogenesbacilli - rod shaped bacteriaex: Escherichia colispirilli - spiral shaped bacteriaex: treponema pallidum(1.3)

What are obligate aerobes?

bacteria that require oxygen for metabolism (1.3)

What are anaerobes?

bacteria that use fermentation or some other form of cellular metabolism that does not require oxygen

What are the types of anaerobes?

obligate anaerobes - can't survive in oxygen environmentfacultative anaerobes - bacteria that can toggle between metabolic processes, using oxygen for aerobic metabolism if present, and switching to anaerobic metabolism if it is notaerotolerant anaerobes - unable to use oxygen for metabolism but are not harmed by its presence in the environment (1.3)

What is one of the main differences between prokaryotes and eukaryotes?

prokaryotes lack nucleus and membrane bound organelles (1.3)

What does it mean for prokaryotes to be single celled?

It means that all of functions necessary for life need to be performed by the cell on its own (1.3)

What advantage can prokaryotes have by living in colonies with other cells?

They can signal other cells to get information about the environment (1.3)

Since prokaryotes are not multicellular organisms, what should they do....

be able to protect themselves from the environment (1.3)

What is prokaryotes cell wall made of?

2 layers:1) cell wall (out)2)cell membrane - composed of phospholipids (1.3)

cell wall + cell membrane = ?

cell envelope (1.3)

What allows the cell to maintain concentration gradient?

The ability of the cell wall to provide structure and control of movement of solutes into and out of bacterium (1.3)

What are the types of cell wall's in bacteria?

*gram positive*gram negative (1.3)

What is gram staining process?

This process determines the type of cell wall process: a crystal violet stain, followed by a counterstain with safranin(+): envelope absorbs stain and becomes deep purple(-): envelope absorbs safranin and becomes pink-red (1.3)

What are gram positive membranes made of?

*thick layer of peptidoglycan*lipoteichoic acid (1.3)

What is peptidoglycan?

polymeric substance made from amino acids and sugars (1.3)

Besides structural and barrier functions what else does cell wall do?

may also aid a bacterial pathogen by providing protection from a host organism's immune system. (1.3)

What is the role of lipoteichoic acid?

The role is not clear in bacteriumBut Human immune system may be activated by exposure to these chemicals. (1.3)

What is a gram negative cell wall made of?

Thin walls with peptidoglycan (1.3)

What is the periplasmic space?

space separating cell walls adjacent to the cell membrane (1.3)

In addition to cell wall & cell membrane. What else do gram negative bacteria have?

outer membranes (1.3)

What are outer membranes composed of?

phospholipids and lipopolysaccharides (1.3)

What trigger the immune system in gram negative bacteria?

Lipopolysaccharides (1.3)

Which inflammatory response is stronger? Lipopolysaccharides or Lipoteichoic Acid

Lipopolysaccharides (1.3)

What are Flagella?

Long, whip-like structure used for propulsion (1.3)

How many flagella can bacteria have?

1,2, or many depending on the type (1.3)

What are chemotaxis?

Ability of a cell to detect chemical stimuli and move toward or away from them (1.3)

What is flagella composed of?

filament, hook, basal body (1.3)

What is fillament?

hollow, helical structure composed of flagellin (1.3)

What is basal body?

complex structure that anchors the flagellum to the cytoplasmic membrane and is also motor of the flagellum, which rotates up to 300Hz (1.3)

What is a hook?

connects the filaments and the basal bodyAs the basal body rotates, it exerts torque on the filament, which thereby spins and propels the bacterium forward. (1.3)

Describe flagella in gram positive and negative bacteria.

Overall structure is similarSlight differences dur to different physical and chemical properties of gram + and - bacteria. (1.3)

Compare flagella of Archaea and bacteria.

Archaea also contain flagellaThe structure is different from that of bacteria. (1.3)

Where do prokaryotes concentrate DNA?

in region called nucleoid region, which doesn't contain nuclear envelope. (1.3)

Where do prokaryotes carry DNA?

On single circular chromosome which can be found coiled, around histone-like proteins in some bacteria. (1.3)

Where do you find true histones?

In Archaea

What are plasmids?

Structured DNA acquired from external sources.DNA which is not needed for survival. (1.3)

What advantage can plasmids give?

Antibiotic resistance (1.3)

Which key organelles are missing in prokaryotes? How are the fulfiled?

Mitochondria is missing.Cell membrane is used for electron transport chain and generation of ATP. (1.3)

Describe cytoskeleton of prokaryotes.

primitive cytoskeleton not nearly complex as in eukaryotes. (1.3)

Describe ribosomes of prokaryotes.

different in size as found in eukaryotesprokaryotic: 30S and 50S subunitseukaryotic: 40S and 60S subunits (1.3)

How do prokaryotes reproduce?

Via asexual reproduction in the form of binary fission (1.4)

What are prokaryotes able to acquire from outside the cell?

they are able to acquire genetic material and use it. (1.4)

what is binnary fission?

simple form of asexual reproduction seen in prokaryotes. (1.4)

What is the process of binary fission?

1) Circular chromosomes attach to the cell wall and replicate while the cell continues to grow in size. 2) Plasma membrane & cell wall grow inward along the midline of cell to produce two identical daughter cells (1.4)

Compare Binary fission & mitosis.

Binary fission requires fewer events than mitosisB.F. proceeds more rapidly (1.4)

Under ideal conditions what can E.Coli do?

replicate every 20 minutes (1.4)

What necessary information does circular chromosome of prokaryotic cell contain?

information necessary for the cell to survive and reproduce (1.4)

How do you call extrachromosomal material bacteria contain?

plasmids (1.4)

How do plasmids benefit bacterium?

1) Antibiotic resistance2) Virulence factors (or traits that increase pathogenicity):* toxin production* projections which allow attachments to certain kinds of cells*features that allow evasion of the hosts immune system

How do you call a subset of plasmids? What are the capable to do?

episomescapable of integrating into the genome of the bacterium (1.4)

What does transformation result from?

results from integration of foreign material into the host genome.

Where does the foreign genetic material come from during transformation?

genetic material frequently comes from other bacteria that, upon lysing, spill their contents into the vicinity of a bacterium capable of transformation. (1.4)

What is able to carry out transformation?

Many gram negative rods. (1.4)

What is conjugation?

bacterial form of mating (sexual reproduction) (1.4)

What is conjugation bridge?

two cells form a bridge that facilitates the transfer of genetic material. (1.4)

Describe transfer in conjugation bridge.

Unidirectional, from donor male(+) to the recipient female (-) (1.4)

What is conjugation bridge made of? Where is material found?

Made of appendeges called sex pili, that are found on the donor male. (1.4)

To form pilus what must bacteria contain?

Must contain plasmids known as sex factors that contain the necessary genes (1.4)

What is the best studied sex factor? How do you call the cells with it?

F(fertility) facto in E.ColiBacteria with plasmid are F+ cells those without are F- cells (1.4)

Describe the process of replication during conjugation.

F= cell replicates its F factor and donates the copy to the F- cell, converting it to an F+ cell. (1.4)

What does the donation of F factor allow?

enables the cell obtaining the new plasmid to them transfer copies to other cells.This work of genetic recombination allows for rapid acquisition of antibiotic resist or virus factors (1.4)

What happens to sex factors during transformation

it can become integrated into host genome (1.4)

why are cell referred as Hfr (High frequency of recombination)?

cells that have undergone transformation and then conjugation.During conjugation the bridge breaks before full DNA sequence can be moved. (1.4)

What is transduction?

only genetic recombination which needs a vector (1.4)

What are vectors?

viruses that carry genetic material from one bacterium to another (1.4)

What are obligate intracellular pathogens?

This is the name for viruses, meaning they can't reproduce on their own (1.4)

What are bacteriophages?

viruses that infect bacteriaCan accidently incorporate a segment of host DNA during assembly (1.4)

When bacteriophages infect another bacterium, they can release trapped DNA into new host cell? What does this lead to?

The transferred DNA can integrate into genome, giving the new host additional genes. (1.4)

What are Transposons? Is this phenomena limited to one place?

genetic elements capable of inserting and removing themselves from the genome. not limited, seen in both prokaryotes and eukaryotes (1.4)

What happens when transposons are inserted into coding region of a gene?

The gene may be disrupted (1.4)

Bacteria reproduce via binary fission. What does this imply?

*All bacteria are exactly the same in local colony. *No bacteria are dividing faster than others (1.4)

What is the series of phases in which bacteria grows?

1) Lag phase2) Exponential phase (Log phase)3) Stationary phase4) Death phase (1.4)

What is log phase?

Phase in which bacteria adapts to the environment.

What is the exponential phase?

when bacteria adapt to the environment rate of reproduction increases, causing exponential increaseAlso called log phase (1.4)

What is the stationary phase?

phase when resources are reduced, and reproduction slows down (1.4)

What is death phase?

After bacteria have exceeded the ability of the environment to support the number of bacteriamaking depletion of resources (1.4)

Draw the process of binary fission

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Draw process of transformation.

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Draw conjugation process?

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Draw process of transduction.

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Draw the bacterial growth curve

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