General Features of Cells and their Organelles

CHLOROPLAST

->Bounded by double membrane ->Inner membrane infolded -> Green due to photosynthetic pigment chlorophyll ->semiautonomous ->has its own DNA and ribosomes -> divided by binary fission (like most prokaryotes)

GOLGI APPARATUS

->Consists of 3-20 flattened, curved cisternae ->Resembles stack of hollow pancakes ->Modifies proteins and lipids -->Packages them in vesicles -->Receives vesicles from ER on cis face -->Prepares for "shipment" in vesicles from trans face

Jobs of the lysosome?

->Digestion of large molecules ->Recycling of cellular resources ->Apoptosis (programmed cell death, like tadpole losing tail)

Smooth ER

->No ribosomes ->Synthesis of lipids ->Many other jobs too, e.g. detoxify, carbohydrate metabolism, Ca2+ storage

PEROXISOME

->Single Membrane-bounded vesicles ->Enclose enzymes ->Enzymes synthesized by free ribosomes in cytoplasm (instead of ER) ->Active in lipid metabolism ->Catalyze reactions that produce hydrogen peroxide H2O2

mitochondrial matrix

->the compartment inside the inner membrane of a mitochondrion ->Inner semifluid containing respiratory enzymes (site of Kreb cycle or Citric Acid Cycle

NUCLEUS

-Command center of cell, usually near center of cell -Separated from cytosol by nuclear envelope ->Consists of double layer of membranes ->Ribosomes on the outside surface ->Contains chromatin in semifluid nucleoplasm ->Dark nucleolus composed of rRNA

fibronectin Structure and Functions

-In the ECM -Connect to integrins (thus connects the ECM to integrins) -abundant flexible -glycoprotein -2 subunits- mRNA spliced differently

where would you find a ribosome? -free ribosome -bound ribosome -mitochondrial ribosomomes -chloroplast ribosomes

-On the outside membrane of the nuclear envelope (bound ribosome) -On the endoplasmic reticulum (making it "rough") (Bound ribosome)) -Free in the cytoplasm, either singly or in groups called polyribosomes (free ribosome) -In mitochondria or chloroplast, these organelle ribosomes are very similar to bacterial ribosomes (chloroplast/mitochondrial ribosome)

Outer Nuclear Membrane Inner Nuclear Membrane Perinuclear Space

-outer nuclear membrane: resembles and continuous with endoplasmic reticulum with ribosome cover -Inner nuclear membrane: Supported by rigid network of protein filaments called nuclear lamina perinuclear space: filled with fluid and continous with the ER

Microtubules Structure Diameter Protein Subunits

1. Hollow tubes; wall consists of 13 columns of tubulin molecules 2. 25 nm with 15-nm lumen 3. Tubulin, consisting of α-tubulin and β-tubulin

Microfilaments/ Actin Filaments Structure Diameter Protein Subunits

1. Two intertwined strands of actin 2. 7 nm 3. Actin

What are the 5 major components of ECM?

1. collagen fibers 2. elastin fibers 3. proteoglycans 4. glycosaminoglycans 5. large adhesive glycoproteins

Intermediate Filaments Structure Diameter Protein Subunits

1.Fibrous proteins supercoiled into thicker cables 2. 8-12 nm 3. One of several different proteins of the keratin family, depending on cell type

Basal Body and Centriole

9 + 0 pattern 9 outer triplets only

Flagella and Cilia

9 + 2 pattern 9 outer doublets and central pair

How do the centrosome and centrioles differ?

A centrosome is a region where microtubule subunits polymerize, it is not a structure per se. Centrioles are a specific structure made from microtubules that are in the centrosome region. Centrioles have a 9 + 0 pattern of microtubules and are always found in pairs that are perpendicular to each other.

actin

A globular protein that links into chains, two of which twist helically about each other, forming microfilaments in muscle and other contractile elements in cells.

flagella

A long cellular appendage specialized for locomotion, formed from a core of nine outer doublet microtubules and two inner single microtubules, ensheathed in an extension of plasma membrane.

How would a white blood cell be affected if it had deficient microfilaments?

A major job of WBC is to phagocytize invading prokaryotic cells. Pseudopods are necessary to do phagocytosis. Microfilaments are necessary to make pseudopods. A WBC could not phagocytize properly if it was deficient in microfilaments.

food vacuole

A membranous sac formed by phagocytosis.

Cytoskeleton

A network of microtubules, microfilaments, and intermediate filaments that branch throughout the cytoplasm and serve a variety of mechanical and transport functions.

CELL WALL

A protective layer external to the plasma membrane in plant cells, bacteria, fungi, and some protists. In plant cells, the wall is formed of cellulose fibers embedded in a polysaccharide-protein matrix. The primary cell wall is thin and flexible, whereas the secondary cell wall is stronger and more rigid and is the primary constituent of wood.

Glycoproteins

A protein covalently attached to a carbohydrate.

cilia

A short cellular appendage specialized for locomotion, formed from a core of nine outer doublet microtubules and two inner single microtubules ensheathed in an extension of plasma membrane.

Who would need a contractile vacuole? A single cell organism living in fresh water (hypotonic solution) or one living in salt water (hypertonic solution)

A single cell organism living in fresh water (hypotonic solution) because there are less solutes; water into the cell

Transport vesicles

A tiny membranous sac in a cell's cytoplasm carrying molecules produced by the cell

phagocytosis

A type of endocytosis involving large, particulate substances. removing large substances

How does the Rough ER modify proteins?

Adds sugar to protein - glycosylation Results in glycoproteins

Secondary Cell Wall

After plant cell matures, deposited between plasma membrane and primary cell wall Layers of cellulose and other components More variable structure than primary cell wall

Do you think integrins are restricted in their movement in the plasma membrane? Why or why not?

Although an integrin is a transmembrane protein and you would think it could move around, it is tethered on the cytosol side by cytoskeletal elements and tethered on the extracellular side by proteins and carbohydrates of the ECM, so it is more restricted.

Why do some cells in an organism have 100 times more mitochondria than other cells?

Because those specific cells require more energy

Bone cells produce high amounts of collagen, why? What happens as these cells age?

Bones need to be able to withstand stress, collagen gives bones their tensile strength to do this. As we age we make less collagen, this means our bones are not as strong an more likely to break

What do chromosomes and chromatin have in common?

Both can be either condensed or uncondensed

What advantage is there in moving chloroplasts around the cell via cytoplasmic streaming?

By moving the chloroplasts around, all will get equal time on the top of the cell where there are more photons of light and the bottom of the cell where there are less photons of light. All the chloroplasts will be able to do equal amounts of photosynthesis overall.

Jobs of Peroxisome?

Catalyze reactions that produce hydrogen peroxide H2O2 ->Toxic ->Broken down to water & O2 by catalase

Characteristics of a cell wall

Cellulose primary cell wall middle lamella secondary cell wall plasmodesmata

The lysosome has a pH of about 4.8, the cytosol has a pH of about 7.2. What would happen if lysosomes in a cell were damaged?

Changes in pH because it would denature proteins

How do cilia and flagella differ? Do they share any commonalities?

Cilia are shorter and found only in eukaryotic cells, flagella are longer and can be found in either prokaryotic or eukaryotic cells. Both are made of microtubules in a 9 + 2 pattern, both are used for movement, though their type of movement is slightly different.

What type of junction would be common between your skin cells? Why?

Desmosomes (anchoring junctions). Skin has a lot of wear and tear, these anchoring junctions act like staples or rivets to maintain the integrity of the tissue

Primary Cell Wall

Develops between newly made cells Flexible and allows for size increase Main macromolecule is cellulose

Why does a eukaryote need a nucleus but a prokaryote does not?

Eukaryotes nucleus' are more specialized and more specific,they have more DNA to organize and more roles to play.

Microfilaments (actin)

Extremely thin filaments like twisted pearl necklace Dense web just under plasma membrane maintains cell shape Support for microvilli in intestinal cells Intracellular traffic control -->For moving stuff around within cell -->Cytoplasmic streaming Function in pseudopods of amoeboid cells Pinch mother cell in two after animal mitosis Important component in muscle contraction (other is myosin)

When skin is cut, how does fibronectin aid in wound healing?

Fibronectin is an adhesive protein that helps hold the two sides of a wound together as new cells fill in the gap

Microtubules (Tubulin)

Hollow cylinders made of two globular proteins called α and β tubulin ->Spontaneous pairing of α and β tubulin molecules form structures called dimers ->Dimers then arrange themselves tubular spirals of 13 dimers around

intermembrane space

Image result for intermembrane space mitochondriaen.wikipedia.org The intermembrane space (IMS) is the region between the inner membrane and the outer membrane of a mitochondrion or a chloroplast. The main function of mitochondrial intermembrane space is oxidative phosphorylation.

What is the advantage of using motor proteins and microtubules to move vesicles?

In a large cell like a eukaryotic cell, microtubules create highways to efficiently move vesicles using the motor proteins on the microtubule highways. There is also the advantage that vesicles reach specified destinations (ie ER to Golgi to Plasma membrane) if there is a highway instead of just relying on diffusion.

If one cell was to influence the development of an adjacent cell, what type of junction might you find? Why?

In an animal gap junctions, in a plant plasmodesmata. Both connect the cytosol of two adjacent cells so signaling molecules can easily travel from one cell to the next by diffusion.

Where are the subunits for Ribosomes made?

In the nucleus

What are the three membranes of mitochondria?

Inter membrane space The Matrix Cristae

How do microtubules cause movement and what is the specific direction with each protein it interacts with?

Interacts with motor proteins kinesin and dynein to cause movement of organelles or vesicles ->Kinesin (fwd + direction) ->Dynein (bkwd - direction)

How would heart function be affected in an individual with mutations in the genes that code for their intermediate filaments? Ie faulty IFs are made

Intermediate filaments are a major component of desmosomes and other anchoring junctions. These staple or rivet like intercellular junctions maintain the integrity of cells in tissue types that take a lot of wear and tear. The heart cells are constantly beating, so they need to be strongly linked together. If you had faulty IFs, you could not make proper desmosomes and heart cells would fall apart from each other.

Intermediate Filaments (keratin)

Intermediate in size between microfilaments (actin filaments) and microtubules Rope-like assembly of fibrous polypeptides Vary Functions: Support nuclear envelope in the nuclear lamina Cell-cell junctions, like those holding skin cells tightly together, e.g. desmosomes

MITOCHONDRIA

Involved in cellular respiration Produce most of ATP utilized by the cell Bounded by double membrane semiautonomous has its own DNA and Ribosomes Divides by Binary Fission (like most prokaryotes)

Centrioles in plant cells

Lower plants have flagellated sperm and therefore need centrioles (e.g. liverworts, moss and ferns). Higher plants have pollen and no need for centrioles

Main Function of Microtubules:

Maintenance of cell shape (compression-resisting "girders") Cell motility (as in cilia or flagella) Cell division (Chromosome movements and cleavage furrow formation) Organelle movements Intracellular movement of cargo (e.g. vesicles)

Main Functions of Intermediate Filaments:

Maintenance of cell shape (tension-bearing elements) Anchorage of nucleus and certain other organelles Formation of nuclear lamina Formation of desmosomes

Main Function of Microfilaments/ Actin Filaments

Maintenance of cell shape (tension-bearing elements) Changes in cell shape Muscle contraction Cytoplasmic streaming Cell motility (as in pseudopodia) Cell division (cleavage furrow formation)

LYSOSOME

Membrane-bound large vesicles (not in plants) Produced by the Golgi apparatus Low pH Enzymes synthesized by free ribosomes in Rough ER Contain lytic enzymes

VACUOLE

Membranous sacs that are larger than vesicles ->Store materials that occur in excess ->Others very specialized (e.g. contractile vacuole, food vacuole, central vacuole)

In eukaryotic cells, what three types of molecular structures compose the cytoskeleton?

Microtubules Microfilaments Intermediate filaments

Do you have to have cellulose to have a cell wall?

No, Fungi cell walls are made primarily of chitin, Bacteria cell walls are made primarily of peptidoglycan, Plant cells are made primarily of cellulose

If a person were taking a drug that kills prokaryotes, would their mitochondria be affected?

No, because it would be protected by the cell wall/ targets something it lost

If a pesticide was developed that kills prokaryotes, would the plants sprayed be harmed?

No, because the pesticide must get past the cell wall

Are all ribosomes found in the cell the same?

No, there are many different types of ribosomes, example --> endosymbiotic vs. attached to organelles

thylakoids

One of a number of disk shaped membranous sacs inside a chloroplast. Thylakoid membranes contain chlorophyll and the enzymes of the light reactions of photosynthesis

Endomembrane system

Organelles that communicate with one another -->via membrane channels -->via small vesicles

Proteoglycans:

Polysaccharide fibers are attached to the core protein. Proteoglycans can aggregate witch GAG and thus they form huge aggregates (aggrecan aggregate in cartilage). Proteoglycans form gels and they are responsible for mechanical properties of the tissue.

trans face "shipping"

Prepares for "shipment" in vesicles from trans face, gives rise to vesicles which pinch off and travel to other sites

Ribosome

Serve as the site of protein synthesis Composed of rRNA and protein Consists of a large subunit and a small subunit Subunits made in nucleolus

integrins Structure and Function

Structure -Receptor proteins built into the plasma membrane. -spans the plasma membrane -Binds to microfilaments of the cytoskeleton via other proteins Function Interconnects the ECM & the cytoskeleton: -By communicating w/ a cell via integrins, the ECM can regulate a cell's behavior. -Intergrins transmit signals betw ECM & cytoskeleton

Rough ER

Studded with ribosomes on cytosol side ->Protein anabolism ->Synthesizes proteins ->Modifies proteins

Which would become more active, Rough ER or Smooth ER, if the cell was induced to produce more protein secretions?

The Rough ER, because ribosomes make proteins for secretion Ex--> the pancrease

What do all the organelles in the endomembrane system share in common?

The biphospholipid layer

Ca2+ is an important signaling molecule between cells including nerve cells. What would happen in a nerve with defective Smooth ER?

The cells would not be able to communicate

stroma

The fluid of the chloroplast surrounding the thylakoid membrane; involved in the sysnthesis of organic molecules from carbon dioxide and water; sugars are made in the stroma by the enzymes of the Calvin cycle

ER Cisternae

The membrane-bound sacs The ER consists of a network of membrane lamellae and tubules called cisternae; the internal space of the ER is called the cisternal space or the lumen

Why are microfilaments the perfect cytoskeletal element to be found in the microvilli?

The microvilli or brush border is where nutrients will come across the plasma membrane to go into the cytoplasm of the cell. The microfilaments within the microvilli then create a "flow" or "river" to move all those nutrients into the middle of the cell for further processing.

Nuclear pore - Why would a hole in the nucleus be useful? What would happen if it was really big?

They allow things to get in and out of the nucleus, if the pores were too big or too small the pores would either let too many substances in or too little substances in.

How would the contents of a trans vesicle differ from a cis vesicle?

They differ because trans vesicles contain the contents for the creation of proteins; contents to make the tertiary shape of proteins.

Do Prokaryotic cells have Flagella and Cilia? if so what are their characteristics?

They have Flagella only and do not have cilia Flagella spins like a propeller Made up of flagellin protein, not tubulin

Do Eukaryotic cells have Flagella and Cilia? if so what are their characteristics?

They have both Flagella and Cilia Flagella move like an undulating wave Cilia move in coordinated waves like oars

Ribosomes on Nuclear Envelope - What would the proteins made here do?

They make the proteins to get into the nucleus

Ribosomal RNA

This is the site of protein synthesis. At this site, all the genetic information copied by mRNA will be translated and New strain of DNA will be produce!

What type of junction would be common between the cells in your gut lining (intestinal epithelium)? Why?

Tight junctions so that all digested monomers have to be properly sorted through the selectively permeable membrane of the intestinal cells and not sneak in between cells.

What is the purpose of having so many thylakoid membranes in a single chloroplast?

To have more surface area, to produce more light energy

Where does the Golgi Apparatus send the packaged vesicles?

To locations within cell Export from cell (secretion, exocytosis)

How would transcription be affected if the nuclear lamina had no intermediate filaments?

Transcription is making RNA from DNA, it requires protein enzymes to get in and read the DNA to then polymerize the RNA. This takes space. If the nuclear lamina had no intermediate filaments, the nuclear shape that is usually spherical or ovoid would collapse and there would not be room to efficiently do transcription.

Would you expect a tree trunk or grass blade to have more layers in their secondary cell wall? Why?

Tree trunk, all the cells are stacked on each other so the bottom cells not only have to resist the forces of gravity, but also the weight of all the cells on top of them. They have more layers in their secondary cell wall to maintain their shape and resist all those downward forces. Much more than a blade of grass which is very small by comparison.

What type of vacuole do plant cells have and why?

Typically have a central vacuole ->Membrane is called the tonoplast ->Up to 90% volume of some cells Functions in: Storage of water, nutrients, pigments, and waste products Development of turgor pressure Some functions performed by lysosomes in other eukaryotes

Glycosaminoglyaans (GAGs):

Unbranched polysaccharides made of repeated disaccharide units. One of the saccharides is an amino-sugar (e.g. N-acetylglucosamin), which is often sulphated, and the second saccharide is an uronic acid (e.g. glucuronic acid).

How does a cell wall in a plant interact with a central vacuole to create turgor pressure?

Water will be stored in the central vacuole such that it will push against the rigid cell wall, this creates turgor pressure. Think of a blown up balloon inside a floppy cardboard box, you attain rigidity with both.

Would you expect the membrane of a central vacuole to be semi-permeable?

Yes, because it is responsible for nutrients and water going in and waste going out

If an infectious agent could disable a lysosome, would this give it a survival advantage, why?

Yes, because the infectious disease would not self end, the lytic enzymes in lysosomes create a programmed cell death, thus if an infectious agent disables a lysosome it would have a survival advantage.

Ribosome location - Does this affect the final job or destination of the protein being made?

Yes- the location directly affects the job the protein needs to complete, proteins are useful for specific jobs thus where the ribosome is depends what protein is needed in that location

Beta cells of the pancreas produce insulin, a protein, would you expect more or less Golgi in these cells, why?

You would expect more because their job is to finalize proteins

autophagy

a PROCESS that mediates turnover of organelles and other intracellular material INSIDE the cell

Nuclear envelope

a double membrane structure containing nuclear pores that creates a perinuclear cisternal space that separates the nuclear compartment of a cell from the cytoplasm. Also there are ribosomes on the outside surface.

myosin

a fibrous protein that forms (together with actin) the contractile filaments of muscle cells and is also involved in motion in other types of cells.

plastids

a general name given to organelles found in plant and algal cells that are bound by 2 membranes and contain DNA and large amount of either chlorophyll(in chloroplast), carotenoids(in chromoplasts), or starch(in amyloplasts)

Chlorophyll

a green pigment located within the chloroplasts of plants, algae, and certain prokaryotes. Chlorophyll "a" can participate directly in the light reactions, which convert solar energy to chemical energy

CENTRIOLES

a microtubule array Short, hollow cylinders Microtubules arranged into 9 overlapping triplets 9 + 0 pattern one pair per animal cell located in centrosome of animal cells replicates just before cell division

Plasmodesmata

a narrow thread of cytoplasm that passes through the cell walls of adjacent plant cells and allows communication between them.

granum

a stack of hollow disks formed of thylakoid membrane in a chloroplast. Grana are the sites where light energy is trapped by chlorophyll and converted to chemical energy during the light reactions of photosynthesis

cellulose

a structural polysaccharide that makes up about 30% of the plant cell wall, which serves many functions: connecting cells to form tissues signaling cells to grow and divide controlling the shape of plant cells allowing cells to withstand the turgor pressure of the fluids inside them

ATP

adenosine triphosphate - all the energy of the cell a nucleotide

cytoplasmic streaming

also called protoplasmic streaming, the movement of the fluid substance (cytoplasm) within a plant or animal cell. The motion transports nutrients, proteins, and organelles within cells

Why do you think a chloroplast or mitochondria has a double membrane?

because it used to be a prokaryotic cell, thus have their own membranes, by follow endosymbiosis theory they were engulfed by cells which explain the double membrane.

Cells in the ovary and testes have more Smooth ER than other cells, why?

because of the location and function, these cells need more hormones and need more regulation of hormones from the SER

Cells in the liver have more peroxisomes than other cells, why?

because they are used to detox, they are active in lipid metabolism and that is what the liver is doing- detoxing toxins put in body.

How do you think vesicles get from one organelle to another in the endomembrane system?

by using microtubules

What are extracellular structures and what are 3 specific types?

components and connections between cells that help coordinate cellular activities include: 1.Cell walls of plants 2.The extracellular matrix (ECM) of animal cells 3.Intercellular junctions

Nuclear Pore Complex

consists of eight proteins inserted between two cytoplasmic and nucleoplasmic rings that mediate transportation in/out of the nucleus

What are the types of specialized vacuoles?

contractile vacuole food vacuole central vacuole

Microtubule Organizing Center (MTOC)

controls the assembly of microtubules, the most important MTOC is the centrosome

cell sap vs. cytosol

cytosol is the watery fluid component of the cytoplasm. The liquid found inside the plant cell vacuole referred to as the cell sap is a dilute fluid consisting of water, amino acids, glucose and salts.

Why is chloroplast green?

due to photosynthetic pigment the chlorophyll which.... ->Captures light energy to drive cellular machinery ->Photosynthesis ->Synthesizes carbohydrates from CO2 & H2O

desmosomes

function like rivets fastening cells together into strong sheets Intermediate filaments reinforce this for anchoring!

Cytoplasm

includes everything inside the plasma membrane --> includes the cytosol, endomembrane system, and the semiautonomous organelles

The Inner Membrane of Chloroplast

is infolded and Forms disc-like thylakoids, which are stacked to form grana (light reactions) Suspended in semi-fluid stroma (calvin cycle)

middle lamella

layer between cell walls of plants

collagen

major insoluble fibrous protein in the extracellular matrix and in connective tissue

tight junctions

membranes of neighboring cells are actually fused forming continuous belts around cell to prevent leakage of extracellular fluid prevents leakage

Nucleolus

non-membranous region(s) varying in size that surrounds transcriptionally active rRNA genes and is the site of rRNA synthesis and initial ribosome assembly

What does the endomembrane system include?

nuclear envelope endoplasmic reticulum Golgi apparatus lysosomes peroxisomes vesicles vacuoles cell membrane

Nuclear pores

openings formed by merging of inner/outer nuclear membranes that create the only way in/out of the nucleus, thus permit exchange between nucleoplasm & cytosol

semiautonomous

organelles that can grow and divide on own but not completely autonomous because they depend on other parts of the cell for internal components

cristae

projections of the highly invaginated inner membrane of a mitochondrion; increases the surface area of the inner membrane site where ATP is made (singular crista) ->Infoldings of inner membrane that encloses matrix (site of oxidative phosphorylation or ETC)

EXTRACELLULAR MATRIX

proteins and carbohydrates outside of the plasma membrane fills the intercellular space and thus it is responsible for mechanical and other physical properties of the tissue (bone, cornea, tendon). largely important for the structure and properties of connective tissue

gap junctions

provide cytoplasmic channels between adjacent animal cells communication

Chromatin

refers generally to a complex of DNA and protein

Chromosomes

refers to a specific stretch of DNA that has specific genes on it

vesicles

small sac enclosed by a lipid bilayer

ER Lumen

space inside the membrane bound sacs

Nuclear lamina

structural network of fibers in nucleus -Contains intermediate filament and lamina associated proteins -Serves as a scaffolding for chromatin and other components of the nucleus -also involved in nuclear organization, cell cycle regulation, and cell differentiation

Cytosol

the region of a eukaryotic cell that is outside the cell organelles but inside the plasma membrane

How would a lack of mitochondria affect the life span of a cell?

they would live less because they would have less energy

Where in the cell would you expect a Golgi to be located, why?

toward the outside of the cell; this is because the Golgi​ apparatus is responsible for secretion. Found between ER & Plasma Membrane

cis face "receiving"

usually located near the ER a vesicle that buds from the ER will add its membrane and the contents of its lumen,cavity, to this face