cells 3 Flashcards

Terms Definitions
Walnut
chloroplast
Makes protein
Ribosome
Lysosomes


Lysosomes are single–membrane–bound centers for storage and/or waste processing (Figure 7.13).
Ribosomes
Proteins are assembled here
Homeostasis
Maintenance of internal stability
eukaryote
unicellular and multicellular... contain a true nucleus and membrane bound organelles
Mitochondria
cellular organelles where cellular resperation occurs
present day atmospheric oxygen concentration is about:
21%
actin
principal protein of the mircrofilaments found in the cytoskeleton of nonmuscule cells and in the thin filaments of skeletal muscle synthesized as a globular monomer(G-actin), that polyerizes into long, linear filaments (F-actin)
Centrosome
Contains centrioles for cellular divisionSome higher plants lack centrioles, but still maintain centrosomeMake microtubules (for what?)
nucleolus
(plural, nucleoli) A specialized structure in the nucleus, formed from various chromosomes and active in the synthesis of ribosomes.
organelles
structures within a cell with specialized functions
Plant cells
Contain chloroplastsIs perforated with plasmodesmataHas a cell wallHas a central vacuole and tonoplastHave no lysosomesHave no centriolesHave no flagella
Lysosome
(4 things)
-Small organelles filled with digestive enzymes
-Digestion of lipids,carbs, and proteins in to smaller molecules than can be used by the rest of the cell
-Break down organelles that have outlived their usefulness
-Fuse with incoming food vacuoles and expose the nutrients to enzymes that digest them
during DNA replication, DNA polymerase initiates a completely new DNA strand from scratch: true or false
false
Which is the largest lymphoid organ?
Spleen
Binary Fission
Process where prokaryote copies internal dna and splits into a new bacteria
Phagocytosis
Membrane invaginates in the vacinity of the particle, and encloses it in a vacuole which breaks away from the membrane. Lysosomes fuse with the vacuole, and release digestive enzymes to break down the particle.
Summarize the structural features of the 3 common DNA-binding domains from Chapter 8.
-
lysosome
a cell organelle containing enzymes that digest particles and that disintegrate the cell after its death.
flagella
(1) structures that aid in locomotion or move fluids across the surface of tissue cells of animals, (2) have protein motor molecules that provide the force for bending and movement, (3) relatively long structures that function as propellers in locomotion, (4) 9 + 2 microtubule arrangement, (5) anchored to cell by basal bodies
conjugation
genetic material is passed via a conjugation bridge
P-type transporter
hydrolyze ATP to drive conformational change
Buffer
Substance that can release and accept hydrogen ions.
Acts as a combination of an acid and base.
*Maintain a pH within specific limits
Cell
Basic unit of life that living organisms are made of; consist of an aqueous solution of organic molecules surrounded by a membrane; cells increase in number by dividing
What energy does DNA helicase use?
ATP hydrolysis
cyclic AMP (cAMP)
adenosine monophosphate with the phosphate group linked to both the 3' and 5' carbons by phosphodiester bonds; functions i both prokaryotic and eukaryotic gene regulation; in eukaryotes acts as a second messenger that mediates the effects of various signaling molecules by activating protein kinase A
Chloroplasts

Most plant and algal cells have chloroplasts that, like mitochondria, grow and divide independently, have a double membrane, and contain chloroplast DNA. Chloroplasts contain everything required to convert light energy to chemical energy (photosynthesis) (Figure 7.18).
Virchow
Observed that cells only come from other cells.
centrosome
Material present in the cytoplasm of all eukaryotic cells, important during cell division; the microtubule-organizing center.
The same enhancer sequence can exist in many genes: T/F
T
cell wall
a rigid layer of nonliving material that surrounds the cells of plants, algae, and some bacteria
ER resident proteins may also be formed into ___________ that prevent them from escaping the endoplasmic reticulum.
Multi-subunit aggregates.
Electron Microscopy
gives resolution ~0.1 nm. (TEM)- sectioned(SEM)- surfacemust be dead- fixed and stained
Where is vimentin found?
Fibroblasts (dynamic during cell division)
what are the macromolecules of sugars, amino acids, and nucleotides?
polysacharidesprotiensnucleic acids
Selectively Permeable
Process by which the cell membrane will choose what comes in and out of the cell.
HIV ‘Rev’
allows unspliced export of RNA from the nucleusUnspliced virus RNA needed for viral particle assembly
Organ System
Organs that work together to perform one of the life processes
nuclear membrane
controls what enters and exits the nucleus
chloroplast
An organelle found only in plants and photosynthetic protists that absorbs sunlight and uses it to drive the synthesis of organic compounds from carbon dioxide and water.
what is alanine scan used in?
site directed mutagenesis
Osmosis
Movment of H2O molecules from a area of high concentration to a area of low concentration across a selectivly permable membrane.
primary cell wall
(1) forms when plant cells secrete cellulose from their plasma membrane, (2) relatively elastic, permitting growth and division
protein and protein folding
proteins- polymers of amino acids joined by peptide bonds O=C-N-Hfolding of the protein is dependent on charges of R group (can be acidic, basic, non-polar, uncharged polar)
RNA transcription - Promoter
~50- 200 nucleotides
core promoter ~ 50 nts, positioned adjacent to transcribed region, contain TAT box, ~7-9 nts often w/ TATA sequence.  Acts as binding site for general transcription factors and Pol II.
DNA synthesis begins at:A. the telomersB. the centromereC. the replication originsD. the CpG islands
C. the replication origins
Define benign, malignant, and metastasis.
benign: tumor that doesn't metastasismalignant: Tending to be severe and become progressively worsemetastasis: The process by which cancer spreads from the place at which it first arose
Cell Theory= 1.)______________2.)________________________3.)_______________________-
1.)Cells are the basic unit of life2.)All organisms are made of one or more cells3.)All cells arise from pre-existing cells.
Golgi Body (Golgi apparatus)
a cytoplasmic organelle that consists of a stack of smooth membranous saccules and associated vesicles and that is active in the modification and transport of proteins.
Cell surface,
Basement membrane appearance and composition?
- Sheet-like structure underlying all epithelia
- Composed of:
a.Basal lamina--composed of type IV collagen, proteoglycans (heparin sulfate), glycoproteins (laminin)
b.Reticular lamina--composed of delicate reticular fibers.
What is the caspase cascade?
When the mitochondria is sufficiently depolarized, cytochrome C escapes and binds to Apaf-1. This aggregate binds to an initiator procaspase, activating it. This then activates other procaspsases until executioner caspsases are activated.
Lipid Solutble Hormone Signaling - Cort Receptors
Transcription activator - typical example of lipid soluble hormone receptors - has a tripartite strucuter - protein has 3 functional modules.
 
TAD -Transcription Activating Domain- Up regulates transcription of target genes by binding to and recruiting coactivator and nucleosome remodeling complexes.
DBD - DNA Binding Domain - responsible for putting receptor on proper target genes by binding to upstream regulatory elements of cort. target genes.
HBD - Hormone binding domain - binds to cort and is required to get receptor into nucleus after cort binds.
Nitric oxide (NO; a gas) acts locally;
-can diffuse across membranes-half-life of about 5-10 seconds-NO can cause muscle cells to relax, increasing blood flow-NO is an important signal molecule in many types of organisms, including plant cells.-NO activates defense mechanisms following pathogen attack-**NO is not N2O, nitrous oxide-laughing gas**-Two examples of medical uses of NO:1. Nitroglycerine, precursor of NO, causes dilation of blood vessels, increasing blood flow to heart, relieving angina2. Viagra (and similar drugs) increases production of NO, results in dilation of blood vessels and increasing blood flow
levels of organization
1. cells 2. tissues 3. organs 4.organ system 5 organism
What are microtubules?
They are hollow rods made up of polymerized tubulins that radiate throughout the cell
What are Chromosomes?
Long pieces of DNA which carry the genes or heredity traits that are passed from parent to child; come in pairs; humans have 23 pairs.
high heat of fusion
a lot of heat must be removed from water before it will freeze
Cells may be organized into tissues
collagen- important protein in animal ECMmost common protein in mammalsfibroblasts- cells of connective tissues (e.g. skin, tendons); produce ECM
How are mitochondria different from other organelles?
They are semiautonomous, which means they contain their own DNA which is circular and ribosomes
what two things can translation rate be controlled by?
initiation factors and translational repressors
What is:(1) Relay protein(2) Messenger protein(3) Adaptor protein(4) Amplifier protein(5) Transducer protein
(1) Protein that passes message from one stage of signal transduction to the next. (2) Carries signal from one part of cell to another(3) Link one signalling protein to another without actually conveying a signal(4) Greatly increase signalling strength(5) Convert a signal into another modality
What is RNA world hypothesis?
Short RNAs catalyze & are templates for their own replication were precursors to living organisms.
What is the cell theory?
-In its modern form, the cell theory includes three principles:

-1. All organisms are composed of one or more cells


2. Cells are the smallest living things


3. Cells arise only by division of a previously existing cell
Cell surface,
Names of Lateral Surface Specializations:
Tight Junction's location,constitution,functionand appearance on micrograph?
- Located near luminal surface of epithelium (will see cilia)
- Formed by fusion of opposed cell membranes
- Constitutes the anatomic component of many barriers in the body: blood-testes barrier.
- Shows sealing strands on freeze-fracture micrograph
What happens when we insert a dominantly active Rho protein into a cell?
Rho acts continually active because it neither hydrolyses ATP, nor interacts with GAP. Because of this the cytoskeleton becomes saturated with stress fibers.
T or F: T cells secrete antibodies.
F: Only B cells secrete antibodies.
what is the role of cholesterol in the plasma membrane?
maintain the cell membrane's fluidity at colder temperatures
In the nucleus are the following structures. Name their function.a. chromatinb. nuclear envelopec. nucleolus
a. packs DNA b. controls flow of materials in and out of nucleusc. produces ribosomes
how often does DNA polymerase make an error during DNA replication?A. one in every 100 nucleotide pairsB. one in every 1000 nucleotide pairsC. one in every 10,000,000 nucleotide pairs
C. one in every 10,000,000 nucleotide pairs
18. The shape of a protein is determined by:
a. the type and order of its amino acidsb. its sizec. its cell locationd. None of the above
centrioles
spindle organization
Na+ cotransporters
Na+/Glucose symporterNa+/K+/Cl- symporterNa+/Ca++ antiporterNa+/Mg++ antiporter
centriole
aid in cell division
Cytoplasm,
Mitochondria: structure?
-Outer membrane.
-Inner membrane.
-Intermembrane compartment
-Matrix
ER
transport of materials throughout cell
New cells come from...
preexisting cells
Bacterial cell
-prokaryotic cell-no membrane-bound organelles still functions in some ways that eukaryotic cells do but without organelles; ex., photosynthesis occurs without chloroplast in cytosol-unicellular organism-cell wall (no cellulose) -conduct cellular activity without organelles-has DNA, but not in nucleus (does not even have a nucleus)-diverse metabolisms ex., nitrogen fixation: bacteria (nitrogen fixers) infects the roots of plants forming nodules (if sliced open, would be red – similarly to hemoglobin); the bacteria takes up gaseous nitrogen from the atmosphere, breaks triple bonds, and changes it into amino acids, which then changes into proteins-exist in “extreme” environments (extremophiles) -temperature, pH, pressure, with or without O2
Prokaryote
Single-celled microorganism that lacks a nucleus
what is a 5' cap?
7-methylguanosine
active transport
energy-requiring process that moves material across a cell membrane against a concentration gradient
nucleus
control center (some cells have it)
What functions to block myosin binding?
Tropomyosin
Plastids
Organelle used for storage of starches, lipids, pigments, etc.
hypotonic
lower solute concentration than cell, water IN
Is the plasma membrane readily permeable?
Yes
Kartagener's syndrome: Presentation
-Male infertility (immotile sperm)
-Female infertility (immotile fallopian cilia)
-Bronchiectasis and recurrent sinusitis (bacteria and particles not pushed out)
-Situs inversus
cytoskeleton
a shifting lattice arrangement of structural and contractile components distributed throughout the cell cytoplasm, composed of microtubules, microfilaments, and larger filaments, functioning as a structural support and transport mechanism.
Louis Pasteur
(1869) performed a series of experiments that disproved spontaneous generation, used two different kinds of flasks: regular and swan-necked
RNA nucelotides
Adenine & uracil guanine & cytosine
Na+/K+ pump functions
regulates osmolaritymajor player in keeping Na+ gradient
MT severing proteins
Katanin, Spastin
 
bind to MT lattice and remove tubulin dimer (suses ATP as energy source)
removal of dimers break M.T.
This breakage results in disassembly because it exposes GDP tubulin
 
which term describes DNA replication?A. conservativeB. semi conservativeC. dispersive
B. semi conservative
nuclear envelope
nucleus is surrounded by 2 membranes
Light Microscope
Usually a compound microscope (more than one lens compounding the image)Advantages of light microscopes1) color images2) larger F.O.V.3) easy to prepare slides4) ability to observe living things (especially movement)
List of Prokaryotic cell structures
Capsule

Cell Wall


Plasma membrane ( cell membrane)


Pilus


Flagella


DNA ( nucleoid region , bacteria chromosome)


Cytoplasm


Ribosomes
Endoplasmic reticulum
a system of interconnected vesicular and lamellar cytoplasmic membranes that functions especially in the transport of materials within the cell and that is studded with ribosomes in some places.
AA + ATP -->
AA-AMP + pyrophosphate (2Pi)
eukaryotic
any organism having as its fundamental structural unit a cell type that contains specialized organelles in the cytoplasm, a membrane-bound nucleus enclosing genetic material organized into chromosomes, and an elaborate system of division by mitosis or mei
cell theory
idea that all living things are composed of cells, cells are the basic units of structure and function in living things, and new cells are produced from existing cells
viruses have a protein coat which is also called a
capsid
cytoskeleton- Eukaryotes vs. Prokaryotes
although prokaryotes don't have microtubules, actin filaments, and intermediate filaments--> they have homologous cytoskeletal structures
Analyzing Data
Determine whether or not data is reliable-Support or refute? 
Uses:
statistics
interpreting graphs
determining relationships between variables
comparing data
What do all cells use to transcribe info?
RNA
Evolution of cells
-All life forms comprised of cells-Simplest organisms are single-celled-More complex organisms are multicellular-Properties of life emerge at level of cell-Proteins and DNA are biologically important and necessary for life, but they are not sufficient for life.
Zinc Finger Motif
use zinc ions to stabilizemultiple typesuse α-helices to recognize DNA
What are the two type of basic cells?
ProkaryotesEukaryotes
Endocytosis
Endocytosis is a process by which the cell membrane can pinch off a vesicle to bring outside material into the cell. In addition to phagocytosis and receptor–mediated endocytosis, a third type of endocytosis called pinocytosis brings fluid into the cell. Pinocytotic vesicles do not go to lysosomes.
Membrane Transport
-Water and other small molecules cross into or out of cells. 


-All cells acquire the molecules and ions they need from their surrounding extracellular fluid (ECF).

-There is an unceasing traffic of molecules and ions
contractile vacuole
A membranous sac that helps move excess water out of certain cells.
is Na+ concentration greater in the cytosol or extracellular fluid?
extracellular fluid
What is the Nucleus?
"Command central"; regulates all activities that take place in the cell; contains chromosomes which contain DNA.
difference between glycoprotein and proteoglycan
glycoproteins are mostly protein, while proteoglycans are mostly carbohydrate
cox1 vs. cox2
cox 1 has good roles-platelet and microphage fxn-mucus formation (ulcers- too much ibuprophen)-hematopoiesis (generation of blood cells)cox2- mostly inflammatory response-may contribue to cancer cell growth
Constitute gene
genes that are transcribed most of the time in most cells.
where in a cell are most damaged proteins broken down?A. peroxisomesB. cytosolC. golgi apparatusD. endoplasmic reticulum
B. cytosol
what do porteins do?
move things across the cell membrane
The Golgi Complex
-Golgi bodies are flattened stack of membranes that are scattered throughout the cytoplasm

-Depending on the cell, the number of Golgi bodies ranges from a few to several hundred


-These are collectively referred to as the Golgi complex


-The Golgi complex collects, packages, modifies and distributes molecules
Define differentiation
When cells are lost they are replaced by cells made by stem cells
16. Only eukaryotic cells have:
a. DNAb. membrane-bound organnellesc. ribosomesd. cytoplasm
What is the function of intermediate filaments? Microfilaments? Microtubules?
Intermediate filaments provide structural strength. Actin microfilaments determine the structure of the cell's skeleton and are essential for whole cell locomotion. Microtubules determine the position of membrane bound organelles.
DNA replication - RPA
Replication protein A - binds single stranded DNA and keeps it single stranded, also binds DNA polymerase A.
homologus recombination
uses the info from other DNA to repair it, can't take place at all times.
Prophase (Early and Late)
1) Early Prophase – Chromosomes are becoming shorter and fatter by supercoiling: spindle microtubules are growing2) Late Prophase- spindle microtubules stretch to opposite poles, and extend from opposite poles to the equator
What do Keratin intemediate filatments provide and explain defects?
mechanical continuity that allows distribution of force across a tissuedefects responsible for hereditary skin disorders that are characterized by cell death in response to mild mechanical trauma
hydrogen bond
a type of chemical bond in which a hydrogen atom that has a covalent link with one of the electronegative atoms (F, N, O) forms an electrostatic link with another electronegative atom in the same or another molecule.
Signaling by lipid soluble hormones
Has potential to move through cell membrane
Receptors usually found inside the cell
Receptors are usually transcription activators
Response usually include change in transcription (also possible changes in metabolism or developmental fate).
Lipid soluble hormone signaling is typically endocrine (best known example, steroids)
single strand binding protein
binds to DNA exposed by helicase so that it does not reform base pairs.
What do ribosomes consist of?
They consist of two subunits, one large and one small
what are transgenic organisms?
organisms which a new gene has been introduced or those whose genomes have been altered using recombinant DNA techniques
other formations of arachidonic acid
elongase can add 2C to other cleaved phospholipidsB oxidation can also remove 2C at a time*for both- desaturase is needed to form the 4 unconjugated double bonds
what does the sliding clamp do?
keeps the polymerase attached to the template by forming a ring around the DNA
Specifically, the smooth is used for what
Includes enzymes that perform certain tasks
Increase the rate of diffusion - Example
glucose enters the cell this way
Primary culture is a good source of cells for cell biology experimentsbecausea) They are mostly genetically identicalb)The connections between cells allow growth factor signals to travelfrom cell-to-cellc)They are a virtually inexhaustible source of cells
Answers: a and dThe connections between cells are destroyed by the addition of trypsinand calcium chelators like EDTA.Primary culture is not an endless supply of cells. Only immortalizedcell lines provide a long-term population of clonal cells.
Why is the central vacuole so important to plants?
It helps stores vital chemicals and waste products. And it can help protect plants against predators.
How are proteins destined for the thylakoid membrane embedded in it?
First they pass through the inner and outer chloroplast membranes, then through the thylakoid membrane into the stroma. Following this, signal peptidase cleaves the N-terminal signalling sequence, exposing a hydrophobic region known as the thylakoid signalling sequence, causing it to be transported to the thylakoid membrane.
What is the result of hypertonic solution, and why is it this way?
The cell is distorted because there is an unequal solute concentration between the solution and the cell
T or F: B Cells and T cells form nodules.
FALSE...only B cells form nodules.
What is myosin II and what does it do?
Myosin II is a 2 headed motor protein that is responsible for muscle contraction and cytokinesis.
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