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347 Cards in this Set

  • Front
  • Back
What is cell theory?
1. cell is the smallest structural functional living unit

2. activity of an organism depends on the individual and collective activities of its cells

3. principle of complementarity of structure and function: the biochemical activities of a cell are determined by its subcellular structure

4. the continuity of life has a cellular basis
Cells differ in what ways?
size, shape, subcellular components and functions
There are over _____ different types of human cells.
200
Human cells have three basic parts. What are they?
1. plasma membrane

2. cytoplasm

3. nucleus
What is the control center of a cell?
the nucleus
What provides the other boundary for a cell?
plasma membrane
What is the intracellular fluid that contains subcellular structures called?
cytoplasm
There are subcellular structures in the cytoplasm. What are they called?
organelles
What is the plasma membrane?
- a double layered membrane composed of phospholipids, cholesterol and proteins

- encloses cellular contents and defines cell boundaries
What does this statement best describe:

" a double-layered membrane composed of phospholipids, cholesterol, and proteins "
plasma membrane
What does this statement best describe:

" encloses cellular contents and defines cell boundary"
plasma membrane
What does it mean to say that the plasma membrane follows a "fluid mosaic model?"
- the plasma membrane is semi-fluid with proteins that float through it in a changing mosaic pattern
What are the components of the plasma membrane?
membrane lipids, membrane proteins and peripheral proteins
What are the three types of membrane lipids that are involved in the plasma membrane?
phospholipids, glycolipids and cholesterol
Phospholipids make up ____ of the lipids in the plasma membrane
75%
What best describes the following statements:

" forms the bulk of the lipid bilayer "
phospholipids
What best describes the following statement:

" has phosphate heads that are polar and hydrophilic "
phospholipids
What best describes the following statement:

" has fatty acid tails that are nonpolar and hydrophobic "
phospholipids
Phospholipids have phosphate heads that are _________.
polar/hydrophilic
Phospholipids have fatty acid tails that are ________.
nonpolar/hydrophobic
Phospholipids have ________ that are polar and hydrophillic.
phosphate heads
Phospholipids have _________ that are nonpolar and hydrophobic.
fatty acid tails
Glycolipids make up _____ of the membrane lipids involved with the plasma membrane.
5%
Glycolipids are lipids with polar _____ groups on outer membrane surfaces.
sugar
________ are lipids with polar sugar groups on outer membrane surfaces.
glycolipids
________ act as adhesives to bind cells together.
Glycolipids
Cholesterol makes up _______ of the lipids involved in the plasma membrane.
20%
Cholesterol are ______ with a polar hydroxyl region and a nonpolar fused ring.
lipids
Cholesterol are lipids with a polar _______ region and a nonpolar fused ring.
hydroxyl
Cholesterol are lipids with a ______ hydroxyl region and a nonpolar fused ring.
polar
Cholesterol are lipids with a polar hydroxyl region and a ________ fused ring.
nonpolar
Cholesterol are lipids with a polar hydroxyl region and a nonpolar ______.
ring
What best describes this statement:

" Increases membrane stability and fluidity "
cholesterol
What is the function of cholesterol?
- to increase membrane stability and fluidity
What is another term for membrane proteins?
integral proteins
What best describes this statement:

" firmly embedded in the membrane"
integral proteins
Integral proteins have both a _______ region and a _______ region, similar to phospholipids.
hydrophobic; hydrophillic
Channels/pores are examples of what type of organic compound?
integral protein
What do channels/pores do in terms of the plasma membrane?
transport small water-soluble molecules and ions across the membrane
What do carriers do in terms of the plasma membrane?
binds to a substance and moves it across the membrane
What do receptors do in terms of the plasma membrane?
- relays signals from hormones or other chemical messengers to the inside of the cell
What best describes this statement:

" binds to a substance and moves it across the membrane "
carrier/transport protein : type of integral protein
What are transport proteins?
a type of integral protein that spans the membrane. It may provide a hydrophillic channel across the membrane that is selective for a particular solute. Some transport proteins hydrolyze ATP as an energy source to actively pump substances across the membrane.
What best describes this statement:

" a type of integral protein that spans the membrane. It may provide a hydrophillic channel across the membrane that is selective for a particular solute."
carrier/transport protein
What are receptor proteins?
- used for signal transduction

- a membrane protein exposed to the outside of the cell may have a binding site with a specific shape that fits the shape of a chemical messenger, such as a hormone. The external signal may cause a change in the shape in the protein that initiates a chain of chemical reactions in the cell.
What best describes this statement:

"a membrane protein exposed to the outside of the cell may have a binding site with a specific shape that fits the shape of a chemical messenger"
a receptor: a type of membrane protein
What are peripheral proteins?
- loosely attached to integral proteins

- form a filament network on the intracellular surface

- include glycoproteins on extracellular surface
Elements of the cytoskeleton and extracellular matrix may be anchored to __________, which help maintain cell shape and fix the location of certain _________.
membrane proteins; membrane proteins.
Some _________ serve as identification tags that are specifically recognized by other cells.
glycoproteins ; type of peripheral protein.
Glycoproteins are a type of _____ protein.
peripheral
What do receptors do in terms of the plasma membrane?
- relays signals from hormones or other chemical messengers to the inside of the cell
What best describes this statement:

" binds to a substance and moves it across the membrane "
carrier/transport protein : type of integral protein
What are transport proteins?
a type of integral protein that spans the membrane. It may provide a hydrophillic channel across the membrane that is selective for a particular solute. Some transport proteins hydrolyze ATP as an energy source to actively pump substances across the membrane.
What best describes this statement:

" a type of integral protein that spans the membrane. It may provide a hydrophillic channel across the membrane that is selective for a particular solute."
carrier/transport protein
What are receptor proteins?
- used for signal transduction

- a membrane protein exposed to the outside of the cell may have a binding site with a specific shape that fits the shape of a chemical messenger, such as a hormone. The external signal may cause a change in the shape in the protein that initiates a chain of chemical reactions in the cell.
What best describes this statement:

"a membrane protein exposed to the outside of the cell may have a binding site with a specific shape that fits the shape of a chemical messenger"
a receptor: a type of membrane protein
What are peripheral proteins?
- loosely attached to integral proteins

- form a filament network on the intracellular surface

- include glycoproteins on extracellular surface
Elements of the cytoskeleton and extracellular matrix may be anchored to __________, which help maintain cell shape and fix the location of certain _________.
membrane proteins; membrane proteins.
Some _________ serve as identification tags that are specifically recognized by other cells.
glycoproteins ; type of peripheral protein.
Glycoproteins are a type of _____ protein.
peripheral
What are the general functions of membrane proteins?
1. act as transport/carrier proteins

2. serve as receptors for signal transduction

3. attachment to the cytoskeleton

4. enzymatic activity

5. intercellular joining
Membrane proteins of adjacent cells may be hooked together in various kinds of _______ .
intercellular junctions.
What is interstitial fluid?
extracellular fluid derived from blood that supplies cells with amino acids, sugars, fatty acids, vitamins, hormones, neurotransmitters and salts
Is interstitial fluid intracellular fluid or extraceullular fluid?
extracellular fluid
Plasma membranes are ______ permeable, meaning they allow some substances to pass through easily and others to be excluded.
selectively
What does it mean to say the plasma membrane is selectively permeable?
the membrane allows some substances to pass through easily and excludes other substances.
What type of membrane transport is best described by the statement :

" No cellular energy required "
passive transport
What type of membrane transport is best described by the statement:

" substance moves down its concentration gradient "
passive transport
What type of membrane transport is best described by the statement:

" uses energy from ATP to transport substances against their concentration gradient "
active transport
What is passive transport?
- no cellular energy required

- substance moves down its concentration gradient
In passive transport, a substance moves ______ its concentration gradient.
down
In active transport, a substance moves ______ its concentration gradient.
up / against
What determines whether or not a substrate can passively permeate a membrane?
- lipid solubility of a substance

- channels of appropriate size

- carrier proteins
What are the types of passive processes?
- simple diffusion

- facilitated diffusion (carrier and channel mediated)

- osmosis

- filtration
Is simple diffusion active or passive?
passive
Is facilitated diffusion active or passive?
passive
Is carrier-mediated diffusion active or passive?
passive
Is channel-mediated diffusion active or passive?
passive
Is osmosis active or passive?
passive
Is filtration active or passive?
passive
What is simple diffusion?
unassisted diffusion of lipid-soluble or very small particles through the bilayer
What best describes this statement:

"unassisted diffusion of lipid-soluble or very small particles through the bilayer"
simple diffusion
What do transmembrane integral proteins transport?
specific polar molecules (like sugars and amino acids )
Sugars and amino acids go across the membrane how?
using transmembrane integral proteins
What is carrier-mediated facilitated diffusion?
when binding of the substrate causes conformational changes in the carrier.
What is facilitated diffusion?
diffusion of substances across the bilayer with the help of channel proteins or carrier proteins.
Certain liphophobic molecules (like glucose, amino acids and ions) pass through the membrane using what process?
facilitated diffusion
Why is facilitated diffusion considered "saturable" ?
because the rate is determined by the number of carriers or channels
What are the types of facilitated diffusion?
carrier mediated and channel mediated
What is channel-mediated facilitated diffusion?
- aqueous channels/ pores formed by transmembrane proteins that selectively transport ions or water
What process is best defined by:

" aqueous channels/pores formed by transmembrane proteins selectively transport ions or water "
channel-mediated facilitated diffusion
What are the two types of channel-mediated facilitated diffusion?
leakage channels and gated channels
What are the differences between leakage channels and gated channels?
leakage channels are always open while gated channels are controlled by chemical or electrical signals
What controls gated channels?
chemical or electrical signals
Leakage channels are _____ open.
always
Mostly ions are selected on basis of ____ and _____ to go through a channel protein.
size ; charge
What is osmosis?
movement of water across the bilayer
How does water diffuse through the plasma membrane?
two ways:

1. through the lipid bilayer

2. through water channels called aquaporins
What is osmolarity dependent on?
the total concentration of all solute particles in a solution
Water concentration depends on the total _______ of solute particles, not the particular _______ of solute particles.
number ; type
When solutions of different osmolarity are seperated by a membrane, osmosis occurs until _______ is reached.
equilibrium
A solution with a higher osmolarity has a high or low concentration of water?
low concentration of water
When a membrane is permeable to both solutes and water, what happens?
- solute and water molecules move down their concentration gradients in opposite directions

- fluid volume remains the same in both compartments
When a membrane is permeable to both solutes and water, solute and water molecules move _____ their concentration gradients in opposite directions.
down
When a membrane is permeable to both solutes and water, solute and water molecules move down their concentration gradients in _______ directions.
opposite
What happens to fluid volume in both compartments when a membrane is permeable to both solutes and water?
fluid volume remains the same, as solute and water molecules move down their concentration gradients in opposite directions.
What happens to fluid volume in both compartments when a membrane is permeable to water and impermeable to solutes?
fluid volume increases in the compartment with the higher osmolarity (meaning had less water, so water moves from more water to less water side).
Can solutions have different volumes and identical osmolarities?
yes; osmolarity is dependent on the total number of solute particles. has nothing to do with the amount of solvent or type of solute!
When osmosis occurs, water does what?
enters or leaves the cell
Why does osmosis matter?
a change in cell volume disrupts its function
What is tonicity?
the ability of a solution to cause a change in cell volume by promoting osmotic flow of water
What happens when a cell is in an isotonic solution?
it has the same solute concentration inside the cell as in the environment

- cells retain their normal size and shape because there is no net movement
What happens when a cell is placed in a hypertonic solution? Why?
- the cell may crenate

- water moves out of cells, so cells may shrink

- less solute concentration and more water outside the cell. Inside the cell, more solute concentration and less water. So, water moves from higher concentration of water to lower concentration of water. So water would move out of the cell
What does it mean to say that cells crenate?
shrink
If a cell is crenating, you can guess that it is in a _________ environment.
hypertonic
If a cell is placed in a hypotonic solution, what would you expect to happen and why?
- Cells may lyse (burst)

- there is a lower solute and higher water concentration in the environment than in the cell. So, water would move from the environment into the cell. So, the cell might burst!
If a cell is lysing, you can guess that it is in a _________ environment.
hypotonic
Does the osmolarity of a cell change when placed in a hypotonic or hypertonic environment?
NO! fluid volume changes.

Osmolarity doesn't change because solutes aren't moving in osmosis!
What is cytoplasm?
- cellular material contained within the plasma membrane; contains cytosol and organelles
What is cytosol?
- viscous fluid in which other cytoplasmic components are suspended

- a portion of cytoplasm

- composed of water and solutes
What are cytoplasmic organelles?
- cellular components with specific functions
What are known as the "metabolic machinery of a cell?"
cytoplasmic organelles
What is composed of water with solutes?
cytosol
Does a nucleus have a membrane?
yes
Do lysosomes have membranes?
yes
Does endoplasmic reticulum (smooth/rough) have membranes?
yes
Do golgi apparatus have membranes?
yes
Do mitochondria have membranes?
yes
Do peroxisomes have membranes?
yes
Do centrioles have membranes?
no
Do ribosomes have membranes?
no
Does the cytoskeleton have membranes?
no
What organelles have membranes?
- nucleus
- lysosomes
- endoplasmic reticulum
- golgi apparatus
- mitochondria
- peroxisomes
What organelles are nonmembraneous?
- cytoskeleton
- centrioles
- ribosomes
What are ribosomes?
- granules containing protein and rRNA

- sites of protein synthesis
What are the sites of protein synthesis?
ribosomes
What forms are ribosomes found in the cell?
free floating and membrane-bound to endoplasmic reticulum (rough)
What organelles are ribosomes sometimes connected to?
rough endoplasmic reticulum
What do free ribosomes do?
- float freely in cytoplasm

- synthesize soluble proteins that remain in the cell
Soluble proteins that remain in the cell are synthesized by ______ ______ (2 words).
free ribosomes
What synthesizes proteins to be incorporated into membranes or exported from the cell?
- Membrane-bound ribosomes (bounded to rough ER)

- rough ER
Free ribosomes float freely in the ________.
cytoplasm
Membrane-bound ribosomes synthesize what kinds of proteins?
proteins to be incorporated into membranes or exported from the cell.
What does the endomembrane system do?
- system of organelles that produce, store, and export biological molecules
What organelles are a part of the endomembrane system?
- nucleus

- nuclear envelope

- rough ER

- Gogli apparatus

- Transport vesicle

- lysosome

- plasma membrane

- vesicle

- smooth ER
What is the structure of rough endoplasmic reticulum like?
- interconnected membranes whose external surface is covered with ribosomes

- continuous with nuclear membrane
What synthesizes membrane integral proteins and phospholipids for cell's internal membranes?
- rough endoplasmic reticulum
What is the structure of smooth endoplasmic reticulum like?
- interconnected membranes whose external surfaces lack ribosomes

- continuous with rough ER
What is smooth endoplasmic reticulum involved in?
- lipid synthesis and metabolism

- detoxification of chemicals and drugs in the liver and kidney

- breaking down glycogen to glucose in the liver

- storing and releasing calcium during muscle contraction
What are lysosomes involved in?
- digestive compartments that break down toxins and old, nonfunctional organelles

- contain digestive enzymes (acid hydrolases)
What is the structure of golgi apparatus like?
- stack of flattened membraneous sacs
What organelle is best described by the following statement:

" lipid synthesis and metabolism "
smooth er
What organelle is best described by the following statement:

" detoxification of chemicals and drugs in liver and kidney "
smooth er
What organelle is best described by the following statement:

" receives products from rough ER "
golgi apapratus
What organelle is best described by the following statement:

" breaking down glycogen to glucose in the liver "
smooth er
What organelle is best described by the following statement:

" storing and releasing calcium during muscle contraction "
smooth er
What organelle is best described by the following statement:

" modifies, concentrates and packages proteins and lipids "
golgi apparatus
What organelle is best described by the following statement:

" transports products to other cellular locations via vesicles "
golgi apparatus
What organelle is best described by the following statement:

" digestive compartments that break down toxins and old, nonfunctional organelles "
lysosomes
What organelle is best described by the following statement:

" contain digestive enzymes "
lysosomes
What is another term for digestive enzymes?
acid hydrolases
What is another term for acid hydrolases?
digestive enzymes
What are mitochondria?
- cellular power plants

- sites of cellular respiration

- generate ATP

- double-membrane structure with cristae to maximize surface area

- provide most of cell's ATP via aerobic cellular respiration

- contain their own DNA and RNA
What structure maximizes the surface area of mitochondria?
cristae
What organelle is best described by the following statement:

" cellular power plant "
mitochondria
What organelle is best described by the following statement:

" sites of cellular respiration "
mitochondira
What organelle is best described by the following statement :

" generate ATP "
mitochondria
What organelle is best described by the following statement:

" double-membrane structure with cristae to maximize surface area "
mitochondria
What organelle is best described by the following statement:

" provide most of cell's ATP via aerobic cellular respiration "
mitochondria
What organelle contain's its own genetic information independent from the cell's DNA/RNA?
mitochondria
What is the endosymbiotic theory?
mitochondria very similar to prokaryotes, used to be their very own organism!
What are peroxisomes?
- membranous sacs containing powerful oxidase and catalase enzymes that detoxify harmful substances

- neutralize dangerous free radicals
what are free radicals?
highly reactive chemicals with unpaired electrons
What is best described by the following statement:

" membranous sacs containing powerful oxidase and catalase enzymes that detoxify harmful substances "
peroxisomes
What is best described by the following statement:

" neutralizes dangerous free radicals "
peroxisomes
What is the cytoskeleton?
- an elaborate network of fibers and rods throughout cytosol

- organizes structure and activities of cells

- made up of microtubules, intermediate filaments and microfilaments
What is made up of microtubules, intermediate filaments and microfilaments?
the cytoskeleton
What is best described by the following statement:

" elaborate network of fibers and rods throughout cytosol "
cytoskeleton
What is best described by the following statement:

" organizes structure and activities of cell "
cytoskeleton
What is best described by the following statement:

" thickest fibers of cytoskeleton "
microtubules of cytoskeleton
What is best described by the following statement:

" dynamic hollow tubes made of alpha and beta tubulins "
microtubules of cytoskeleton
Microtubules are dynamic hollow tubes made up of alpha and beta ________.
tubulins
What is best described by the following statement:

" serve as tracks along which organelles can move "
microtubules of cytoskeleton
What is best described by the following statement:

" centrosome/microtubule organizing center, anchoring points from which microtubules radiate "
microtubules of cytoskeleton
What determines the shape of cell and distribution of the organelles?
microtubules of cytoskeleton
What are microtubules?
- thickest fibers of cytoskeleton

- dynamic hollow tubes made up of alpha and beta tubulins

- serve as tracks along which organelles can move

- determines overall shape of cell and distribution of organelles
What are intermediate filaments?
- cytoskeleton fibers thinner than microtubules but thicker than microfilaments

- tough, insoluble ropelike protein fibers
What do the intermediate filaments do?
- resist pulling forces on the cell
What are the most stable cytoskeletal elements?
intermediate filaments
What part of the cytoskeleton is made up of keratin fibers?
intermediate filaments
intermediate filaments are made up of ______ fibers
keratin
Cytoskeletal fibers are ______ than microtubules but ______ than microfilaments
thinner ; thicker
Intermediate filaments are tough, insoluble protein fibers constructed like __________.
rope
What are the thinnnest cytoskeleton fibers?
microfilaments
What part of the cytoskeleton is made of actin protein?
microfilaments
What do microfilaments do?
resist compression and generate contractile force
What is best described by the following statement:

" resist compression and generate contractile force"
microfilaments
Microfilaments are made of spherical protein subunits called ______.
actin
What are cellular extensions?
- cilia, microvilla and flagella

- short projections present on the outer surface of certain cell types
What are cilia?
- short, whiplike appendages

- move substances over the cell's surface

- made of microtubules arranged in a "9+2" arrangement
What is best described by the following statement:

" short, whiplike appendages "
cilia
What are flagella?
- longer appendages that help propel the entire cell

- made up of microtubles arranged in a " 9+2" arrangement
What are microvilli?
- short, fingerlike projections of the plasma membrane

- increase the surface area for absorption

- contain a core of actin filaments for stiffening
What is best described by the following statement:

" longer appendages that help propel the entire cell "
flagella
What is best described by the following statement:

" increase surface area for absorption "
microvilli
What is best described by the following statement:

" contain a core of actin filaments for stiffening "
microvilli
What is best described by the following statement:

" control center of the cell "
nucleus
What is best described by the following statement :

" largest cellular organelle"
nucleus
What is best described by the following statement:

" contains a nuclear envelope, nucleolus and chromatin "
nucleus
What is the nucleus?
- control center of the cell

- contains the DNA

- largest cellular organelle

- contains the nuclear envelope, nucleolus, and chromatin
What does it mean to say that most cells are uninucleate?
have one nucleus
What is an example of a cell that is uninucleate?
red blood cell
What is an example of a cell that is multinucleate?
skeletal muscle cells, bone destruction cells and some liver cells are multinucleate
What does it mean to say that a cell is multinucleate?
has many nuclei
What is the nuclear envelope?
- double membrane barrier sounding the nucleus

- nuclear lamina - inner lining that helps maintain nuclear shape

- nuclear pores - channels for transporting mRNA in and out of nucleus
What is best described by the following statement:

" channels for transporting mRNA in and out of the nucleus "
nuclear pores
What is best described by the following statement:

" inner lining that helps maintain nuclear shape "
nuclear lamina
What are nuclear pores?
channels for transporting mRNA in and out nucleus
what is the nuclear lamina?
inner lining that helps maintain nuclear shape
What is the nucleolus?
- dark staining spherical body within nucleus

- involved in rRNA synthesis and ribosome subunit assembly
What is best described by the following statement:

" dark-staining spherical body within nucleus "
nucleolus
What is best described by the following statement:

" involved in rRNA synthesis and ribosome subunit assembly"
nucleolus
What is chromatin?
- a complex of DNA, histone proteins, and RNA

- arranged in fundamental units called nucleosomes

- condenses into chromosomes for cell division
Chromatin condenses into _______ for cell division.
chromosomes
Chromatin is arranged in fundamental units called ________.
nucleosomes
what are "little balls of protein with DNA wrapped around them"?
histones
What defines the life stages of a cell from formation to reproduction?
cell cycle
What is the cell cycle?
defines the life stages of a cell from formation to reproduction
Why do cells divide?
- organism growth

- tissue repair

- surface area to volume ratio
Explain why cells need to divide to maintain surface area to volume ratio.
surface area doesn't increase at the same rate as volume. You need more surface area .... meaning you need more plasma membrane. So to get more plasma membrane, you divide!
What are the two major phases of the cell cycle?
interphase and the mitotic phase
What is interphase?
the period from cell formation to cell division (cell grows and carries out usual functions )
What phase of the cell cycle is best described by the following statement:

" the period from cell formation to cell division "
interphase
What is the mitotic phase?
when cell divides into two identical daughter cells
What phases are within interphase?
G1, S and G2
What is the G1 phase?
- first part of interphase

- gap 1 = vigorous growth

- the cell is metabolically active

- g1 checkpoint/restriction point

- g0 = nondividing phase, go to if fail g1 checkpoint
What is the G1 checkpoint?
the point cells have to pass in order to reach the S phase
What happens if cells fail at the G1 checkpoint?
they enter G0, a non-diving stage that cells enter if they fail to pass restriction point
How long do cells normally stay in G1?
no time limit, can last few days or many years
The cell cycle is ________.
continuous
What is the S phase of interphase?
- synthesis phase

- DNA is replicated, resulting in two identical copies of the genetic material
What is the G2 phase?
- gap 2 phase of interphase

- preparation for division

- synthesis of proteins needed for mitosis

- G2 checkpoint
What is the G2 checkpoint?
- checkpoint between G2 and mitosis

- cell must have adequate mitotic promoting factor to enter mitosis
Cells must have adequate ___________ to enter mitosis, as checked in the G2 checkpoint.
mitotic promoting factor
What phase is best described by:

" DNA is replicated "
S phase of interphase
What phase is best described by :

" cell is metabolically active "
G1 of interphase
What phase is best described by:

" synthesis of proteins needed for mitosis "
G2 of interphase
What is best described by:

" checkpoint that cells must pass in order to enter S phase "
G1 checkpoint
what is best described by the following statement:

" non-diving stage that cells enter if they fail to pass G1 checkpoint "
G0
What happens if cells don't have enough mitotic promoting factor?
won't enter mitosis; fail G2 checkpoint
What phase is best described by the following statement:

"vigorous growth"
G1 of interphase
What phase is best described by the following statement:

" preparation for division "
G2 of interphase
What are the stages of mitosis?
1. prophase

2. metaphase

3. anaphase

4. telophase
- cytokinesis

followed by a return to interphase
Where does a cell go after it has finished mitosis?
back to interphase!
What is the formal definition of mitosis?
- splitting of the nucleus
Mitosis does not occur in most mature cells of _________ tissue, _______ muscle, and ______ muscle.
nervous, skeletal, cardiac
Mitosis is a _______ process.
continuous
What phase is best described by the following statement:

" chromatin condenses into chromosomes (with two chromatids joined at the centromere) "
prophase
What phase is best described by the following statement:

" mitotic spindle forms "
prophase of mitosis
What phase is best described by the following statement:

" centrosomes migrate toward opposite poles "
prophase of mitosis
What phase is best described by the following statement:

" nuclear envelope breaks down "
prophase of mitosis
What happens in prophase of mitosis?
- chromatin condenses into chromosomes (with two chromatids joined at the centromere)

- mitotic spindle forms

- centrosomes migrate toward opposite poles

- nuclear envelope breaks down
Chromatin condenses into chromosomes (with two chromatids joined at the ________ )
centromere
What phase is best described by the following statement:

" centromeres of chromosomes are aligned at the cell's equator "
metaphase of mitosis
Chromosomes line up along what during metaphase of mitosis?
the metaphase plate
During which phase do chromatids become chromosomes?
anaphase
What is metaphase of mitosis?
- centromeres of chromosomes are aligned at the cell's equator, causing chromosomes to line up along this midway plane called the metaphase plate
What happens during anaphase of mitosis?
- centromeres of chromosomes split simultaneously- each chromatid now becomes a chromosome
What phase is best described by the following statement:

" chromosomes are pulled toward poles by motor proteins along the microtubule tracks "
anaphase of mitosis
What phase is best described by the following statement:

" begins when chromosome movement stops "
telophase of mitosis
What phase is best described by the following statement:

" the two sets of chromosomes uncoil/ decondense back into chromatin "
telophase of mitosis
What phase is best described by the following statement:

" new nuclear membrane forms around each chromatin mass"
telophase of mitosis
What phase is best described by the following statement:

" nucleoli reappear "
telophase of mitosis
What phase is best described by the following statement:

" spindles break down "
telophase of mitosis
What is telophase of mitosis?
- begins when chromosomes stop moving

- the two sets of chromosomes uncoil/decondense back into chromatin

- new nuclear membrane forms around each chromatin mass

- nucleoli reappear

- spindles break down
Cytokenesis actually begins during _____________.
late anaphase
What is best described by the following statement:

" not a specific phase but a description of the cytoplasmic pinching process"
cytokenesis
What is best described by the following statement:

" ring of actin microfilaments contracts to form a cleavage furrow "
cytokenesis
What is formed during cytokenesis?
a cleavage furrow
What is best described by the following statement:

" two daughter cells are pinched apart, each containing a nucleus identical to the original "
cytokenesis
What is essential for growth and maintenance of the cell?
protein synthesis
What occurs during cytokenesis?
- ring of actin microfilaments contracts to form a cleavage furrow

- two daughter cells are pinched apart, each containing a nucleus identical to the original
What is the central dogma of molecular biology?
DNA ---> mRNA ----> protein
What is a gene?
a segment of DNA that describes the instructions for creating a polypeptide chain
What is best described by the following statement:

" a segment of DNA that describes the instructions for creating a polypeptide chain"
gene
A gene is _________ to form mRNA.
transcribed
An mRNA molecule is _________ to form a protein.
translated
Protein synthesis can be divided into three steps. What are they?
1. transcription

2. pre-mRNA processing

3. translation
Where does transcription occur?
in the nucleus
Where does pre mRNA processing occur?
in the nucleus
Where is mRNA formed?
in the nucleus
Where does translation occur?
in the cytosol / free floating ribosome
Where is protein officially synthesized?
in the ribosome in cytosol
What is the definition of transcription?
the synthesis of mRNA from a DNA template
Transcription is the synthesis of _______ from ________.
mRNA ; DNA template
Transcription occurs in three stages. What are they?
1. Initiation

2. Elongation

3. Termination
Transcription factors bind to the _________, a sequence specifying the start of the gene.
promoter region of DNA
What are transcription factors?
they bind to the promoter and signal the RNA polymerase to bind to DNA to initiate transcription.
Transcription factors bind to the promoter region of DNA, a sequence specifying the _________ of the gene.
start site
Transcription factors signal the binding of _________ near the start site.
RNA polymerase
___________ binds to the promoter, pries the two DNA strands, and initiates mRNA synthesis at the start point on the template strand.
RNA polymerase
RNA polymerase initiates mRNA synthesis at the start point on the _______ strand.
template
The mRNA formed will have the same sequence as the ________ strand of DNA. (except thymines will be replaced with uracils)
coding
The mRNA formed will have a sequence complementary to that of the _______ strand of DNA.
template
RNA polymerase enzyme does what?
oversees the synthesis of mRNA by unwinding the DNA template and moving along the DNA to add nucleotides to the mRNA that complement the DNA template strand
RNA polymerase _______ the DNA template.
unwinds
RNA polymerase moves along DNA and adds _________ to the mRNA that complement the DNA template strand.
nucleotides
As the RNA polymerase moves along the template strand, elongating the mRNA transcript one base at a time it ______ the DNA double helix before it and rewinds the double helix behind it.
unwinds
At any given moment, 16-18 pairs of DNA are unwound and the most recently made RNA is still bound to DNA. This small region is called the _________.
DNA-RNA hybrid.
RNA polymerase reaches the gene's ___________ on the DNA, and releases pre-mRNA.
termination signal
mRNA synthesis ends when?
When RNA polymerase reaches the termination signal. RNA polymerase and the completed mRNA transcript are released
What occurs during pre-mRNA processing?
1. RNA splicing

2. Cap and tail are added to mRNA
What does it mean to say that RNA is "spliced?"
- introns (intervening sequences) are removed by spliceosomes

- exons (expressed sequences are brought together to form mRNA)
What are introns?
intervening sequences that are removed from the final mRNA product during pre- mRNA processing by spliceosomes
What are exons?
expressed sequences that are joined together during pre-mRNA processing.
Where are introns sliced out of the RNA product?
in the nucleus
mRNA is transported out of the ______ into the cytoplasm right before translation.
nucleus
mRNA is transported out of the nucleus into the ________ for translation.
cytosol
What is translation?
the synthesis of a polypeptide from an mRNA template.
What process is best described as:

" the synthesis of a polypeptide from an mRNA template "
translation
What three types of RNA are involved in translation?
mRNA, tRNA and rRNA
What is best described by the following statement:

" carries instructions for building a polypeptide, from gene in DNA to ribosomes in cytoplasm "
mRNA
What is best described by teh following statement:

" a structural component of ribosomes that, along with tRNA, helps translate message from mRNA"
rRNA
What is best described by the following statement:

" Bind to amino acids and pairs with bases of codons of mRNA at ribosome to begin process of protein synthesis"
tRNA
During translation, sets of three nucleotides called ______ specify each amino acid.
codons
What are codons?
sets of three nucleotides that specify a particular amino acid
What do mRNA's do in protein synthesis?
carry instructions for building a polypeptide from gene in DNA to ribosomes in cytoplasm
What do rRNA's do in protein synthesis?
serve as structural components of ribosomes
What do tRNA's do in protein synthesis?
bind to amino acids and pair with bases of codons of mRNA at ribosome to begin process of protein synthesis.
tRNA's bind to ________ and pair with bases of codons of mRNA at ribosome to begin process of protein synthesis.
amino acids
tRNA's bind to amino acids and pair with bases of _______ of mRNA at _______ to begin process of protein synthesis.
codons ; ribosome
a tRNA molecule carrying the complementary anticodon and the corresponding amino acid binds to the ______ during translation
codon
a tRNA molecule carrying the complementary _________ and the corresponding amino acid bind to the codon during translation.
anticodon
a tRNA molecule carrying the complementary anticodon and the corresponding ________ bind to the codon during translation.
amino acid
mRNA attaches to the ______ during translation.
ribosome
a _______ molecule carrying the complementary anticodon and the corresponding amino acid bind to the codon during translation.
tRNA
a tRNA molecule carrying the complementary anticodon and the corresponding amino acid bind to the codon during _________.
translation
_______ attaches to the ribosome during translation.
mRNA
The first codon enters the " _____ " site of the ribosome.
A
the first ______ enters the " A " site of the ribosome
codon
The first codon enters the "A" site of the ________.
ribosome
the ribosome moves along the ______ strand during translation.
mRNA
Codons move from the "A" site to the "_____" site to the "E" site while being read by the ribosome during translation.
P
Codons move from the "A" site to the "P" site to the _____ site while being read by the ribosome during translation.
E
After leaving the "E" site, the tRNA is released back into the cytoplasm where a new _______ will be attached to it.
amino acid
When the ribosome reaches the stop codon on the mRNA, what happens?
the polypeptide is released
What has to happen for the polypeptide to be released during translation?
the ribosome has to reach the stop codon.