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Biology 151
Trisha
76
Biology
Undergraduate 1
02/21/2009

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Term
STROMA
Definition
Space inside inner membrane
Term
THYLAKOID
Definition
internal membrane-bound structures of chloroplasts
Term
Chloroplasts are surrounded by how many membranes?
Definition
two membranes
Term
When Thalakoids are stacked together, what are the stacks called?
Definition
Granum
Term
What is the chemical equation of photosynthesis?
Definition
6CO2+ 6H2O + Light energy yields C6H12O6+ 6O2
Term
Light dependent reactions occur in what part of the plant cell?
Definition
thylakoid
Term
Where does the calvin cycle occur?
Definition
The calvin cycle occurs in the stroma
Term
Which property of light is important for the photosynthetic process?
Definition
the particle property of light
Term
Which is the most important pigment in Photosynthesis?
Definition
Light is absorbed by the pigment chloryphll
Term
What types of chloryphyll are there in photosynthesis? What part of the molecule makes them distinguishable?
Definition
The types of chloryphyll that are in photosynthesis are chloryphyll A and B, the magnesium ion in the cation in the center of the molecule makes them distinguishable
Term
What are the two general parts of chloryphyll a and b?
Definition
There is a polyphorin ring as well as a hydrocarbon tail
Term
What are carotenoids?
Definition
caroteniods are extra pigment that help absorb the different wavelengths of excessive light in order to protect the chloryphyll
Term
When leaves turn orange and yellow, what is happening?
Definition
The Chloryphll from the leaves are degraded
Term
When light excites an electron, the electron reaches an excited state before returning back to its ground state. Upon returning to its ground state, what must the electron give off?
Definition
The electron releases heat and a photon which can be used for fluoresence.
Term
How many photosystems are there? What do they do?
Definition
There is photosystem I and II (two comes first, one comes second). These photosystems use light and pigment to excite an electron and donate an electron acceptor. They harvest light.
Term
What is in the reaction center of the photosystems?
Definition
there is two chloryphyll a molecules as well a a primary electron acceptor in the reaction center.
Term
What is the chloryphyll at photosystem II called?
Definition
p680
Term
What is the chlorophyll at photosystem II called?
Definition
p700
Term
Describe the steps of Photosystem I and II for noncyclic flow
Definition
  1. Light enters photosystem II and its electrons are passed between various chlorophyll pigments until it reaches the Chloryphyll A (P680) at the reaction center
  2. These electrons are transferred to the primary electon acceptor
  3. Water is transferred to the chlorophyll a (p680) and yields hydrogen, oxygen, and electrons. Those electrons are also transferred to the primary electron acceptor.
  4. The electrons then are put through an electron transport chain to the Chlorophyll a (p700) in photosystem I
  5. In the process of the electron transport chain, Atp is formed via H+ pumps and ATP synthase.
  6. Light enters photosystem I and is transferred from chlorophyll to chlorophyll till it reaches chlorophyll A (p700) of the reaction center. These electrons, as well as the electrons from the electron transport chain are transferred to the primary electron acceptor
  7. From the primary electron acceptor the electrons are put through an electron transport chain
  8. The electrons are transferred from the NADP+ to NADPH
Term
Where does the ATP synthase receive hydrogens to create ATP
Definition
The H+ recieved from when water is converted to oxygen is put into the ATP synthase as well as hydrogen from the electron transport chain. The hydrogen is transported through the thylakoid space to the other side of the thylakoid membrane to reach the ATP synthase
Term
Describe the cycle of cyclic flow in photosynthetic process
Definition
The cyclic flow really only deals with photosystem II. It starts with when the electrons are in the primary electron acceptor of photosystem II. These electrons are then cycled back to the previous electron transport chain, which causes more ATP to be made in the ATP synthase as the electron are being passed through the chlorphyll A (p700) to the primary electron acceptor to start the cycle process all over again.
Term
 True or false: Photosystems I and II occur in the same regions of the thylakoidmembrane
Definition
false, they occur in separate regions of the membrane
Term
Plant grown in the dark are yellow because:
Definition
They lack chlorophyll
Term
What is the main purpose of the calvin cycle?
Definition
The calvin cycle synthesizes sugar from co2
Term
How many stages are there in the Calvin cycle?
Definition
There are 3 steps, fixation, reduction, and regeneration
Term
What happens during fixation of the calvin cycle?
Definition
The rubisco enzyme catylzes 5 carbon chains with co2 to yield two 3 carbon chains with a phosphate group. 3 co2 enter the cycle one at a time and in the process  6 ATP is used up to 6 ADP
Term
What happens in reduction of the calvin cycle?
Definition
NAPDH is used to the glyceraldehye and made into a g3p sugar as an output
Term
What happens during regeneration process of the cycle?
Definition
In this process, it works are the reneration of the co2 acceptor(ribulose biphosphate). in the process, 3 ATP is used up
Term
How many CO2 molecules does it take to make 1 3 carbon g3p sugar?
Definition
it takes 3 co2 molecules
Term
In the calvin cycle process, Rubisco adds three CO2molecules to three 5-carbon chain RuBPsto make ?
Definition
six 3-carbon chains
Term
How many G3P sugars does the calvin cycle actually make?
Definition
6 G3p sugars
Term
Since only 1 G3p is removed from the calvin cycle, where do the other ones go?
Definition
They are used to regenerate three 5-carbon RuBPs
Term
The calvin cycle uses how much NADPH and how much ATP?
Definition
Uses 9 ATPs, 6 NADPHs
Term
Give the full equation of the calvin cycle
Definition
3CO2+ 9 ATP + 6 NADPH + H2O G3P + 8 Pi + 9 ADP + 6 NADP+
Term
Sugars are exported from leaves to go where?
Definition
The rest of the body
Term
How does plants obtain co2?
Definition
CO2 diffuses through stomatal pores on leaves
Term
When the stomata open to let co2 in, what comes out of them?
Definition
water
Term
Out of photorespiration and photosythesis, what is the more preferable process? why?
Definition
Photosynthesis is the most effecient using rubisco when it has affinity for co2 rather than when it has o2 affinity during photorespiration. When photorespiration is used, nrg is lost.
Term
It is estimated that photosynthesis rates can be reduced by ____due to photorespiration
Definition
50%
Term
What is the probem with rubisco when it comes to photorespiration and Photosynthesis?
Definition
Rubisco evolved more than 3 billion years ago, when atmospheric O2was rare and CO2 levels were high
Term
Conditions that favor photorespiration (Rubiscooxygenaseactivity):
Definition
•High O2/CO2ratios
•High light intensity
•High temperatures
Term
To overcome the effects of photorespiration some plants have evolved a ____photosynthetic pathway
Definition
C4
Term
When is C4 more avantageous than C3?
Definition

•Where light is a limiting factor and temperatures are low (i.e. in temperate climatic zones) have C3 plants the advantage.


•C4 plants are more successful in the open country of warmer zones.

Term
What is so different about c4 from c3?
Definition
The co2 cycle of harvesting energy is processed in the  mesophyll cell where is forms a 4 carbon compound. The process of the calvin cycle is done in the bundle sheath which then has more affinity for co2 and decreases the likelihood of photorespiration and the energy of sugar is store in the vascular tissue
Term
What is the biggest difference in the CAM cycle than other cycles?
Definition

The CrassulaceanAcid Metabolism (CAM)
Night: stomata are open
Day: stomata are closed

 

For the night, the  malic acid is stored in the vacuole until the daytime where malete is made into Co2 and put through the calvin cycle in the chloroplasts. 

Term
Difference between CAM and C4?
Definition

C4- there is a spatial separation of steps, things occur in different parts of the cell.

CAM- the steps are separated in night and day. 

Term
Define colony:
Definition
Collection of individuals
Colonies of cells in prokaryotes and protist(eukaryotes)
Term
Describe the signal procedure of Dictyostelium coming together to make spores
Definition
one single cell organism starts to make a signal that attracts other organisms to make it seem like they are forming one big organism. Then the group makes a tail and a spore and all cells in the tail will die in order to the cells in the spores to be formed.
Term
There is “true” multicellular life in:
Definition
•PLANTS
•ALGAE
•FUNGI-
e.g. mushrooms
•ANIMALS
Term
In comparison to unicellular organisms, cells in multicellularorganisms are expected to have:
Definition
A.More genes
Term
How do the cells remain together for animals?
Definition
No cell wall, but jelly-like EXTRACELLULAR MATRIXHow
Term
How do cells remain together in plant cells?
Definition
Plant cells have a polysaccharide cell wall: main component is cellulose
Term
Types of Cell junctions
Definition

1-Occluding junctions: seal cells together to make impermeable barriers (tight junctions in epithelia)

 

2-Anchoring junctions: mechanically attach cells (and their cytoskeleton) to their neighbors (desmosomes)


3-Communicating junctions: create passageways linking the cytoplasm of adjacent cells (septalpores in fungi; gap junctions in animals; plasmodesmatain plants)

Term
Occluding junctions are important for proventing ___ of cells
Definition
leakage, does this by providing tight junctions of epithelial cells
Term
anchoring junctions
Definition
combines 2 plasma membrane of cells
Term
communicating junctions
Definition
Membrane proteins (connexins) from adjacent cells line up to form a channels.
Term
What can pass in communicating junctions?
Definition
Inorganic ions and other small water-soluble molecules can pass through gap junctions
Term
Epithelial cells can have which of the junctions?
Definition

all three:

Occluding junctions (Tight junctions)

Anchorage junction (desmosomes)

Communicating junctions(gap junctions)

Term
Descirbe the communicating junctions for plants cells
Definition
Plasmodesmata: pores in cell walls connect cytoplasmaand plasma membrane, one continous cycle of the endoplasmic reticulum and plasma membrane
Term
How do cells communicate with each other?
Definition
Communication by direct contact
Term
What can each type of plant pass through with direct contact?
Definition

Fungi (and other syncytialcells)-pores can pass organelles, large molecules

 

Plants: RNA can pass through plasmodesmata.

 

 

Animals: only ions and monomers pass through gap junctions.

Term
How do cells communicate without cytoplasmic connections?
Definition
One cell produces SIGNALING MOLECULE (‘ligand’) and this signal will Bind to RECEPTOR protein in receiving cell, changes its activity
Term
what are the three basic steps of cell signaling?
Definition

1.Reception: detection of signal molecule outside the cell. Receptor-ligandbinding

 

2.Transduction: Conversion of the signal to a form that can trigger a cellular response


3.Response: it could be activation/deactivation of enzymes; gene transcription; rearrangement of cytoskeleton, etc.

Term
types of cell signaling?
Definition
  1. contact dependent- the signaling of a molecule that then binds to a recptor and needs contact btwn cells.
  2. paracrine- secreting a ligand and the target cells are in the vicinity so they wont stray far away from the cells
  3. synaptic- the body of the cells have very long projections that get very close to the cells and there are electrical impulses that run along and release neurotransmitters
  4. endocrine- signaling molecules(hormones) that goes into the blood stream tthat go from molecule to target cell
Term
true or false: Receptors can be located at the plasma membrane (surface receptors) or inside the cell
Definition
true!
Term
intracellular receptors for cell signaling need carrier proteins that are hydrophobic or hydrophilic?
Definition
hydrophoblic
Term
This type of cell signal that
Is lipid, can diffuse through cell membranes
Steroid receptor is protein incytoplasm and nucleus Testosterone, estrogen, etc.
Definition
steroids
Term
how does SIGNAL TRANSDUCTION PATHWAY from receptor to cellular response work?
Definition
Intracellular receptors for steroids hormones: receptor-steroid complex binds to DNA.
Complex blocks or helps “expression” of some mRNAs from DNA (transcription)
Term
This kind of cell signaling cannot diffuse through cell membranes, so receptor on cell membrane (cell-surface receptors), what is it?
Definition
Protein, peptide and amino acid signals
Term
Types of cell-surface receptors
Definition
  1. ION CHANNEL RECEPTORS- active transport of ions that the signal attaches itself to the gate to open it and allow the ions to pass through until the signal detaches itself from the cell.
  2. receptor protein kinases-the signals will attach itself to the cell and two tyrosine proteins will come together to form a dimer. phosphorylation of this dimer will happen and activate the protein which in turn can activate another protein. 
Term
Transduction
Definition
Getting signal from
membrane and its a CASCADES of kinases one protein can activate another protein which can activate another protein, etc
Term
G-PROTEIN-linked receptor
Definition
Inactive G-protein binds GDP (like ADP, but with guanosine) Receptor causes GTP to bind instead, activating G protein Active G protein activates another protein
Term
SECOND MESSENGERS
Definition

 

small non-protein molecules

 

a)Cyclic AMP (cAMP), made by ADENYL CYCLASE enzymes
b) IP3(inositol1,4,5-triphosphate ) and DAG (diacylglycerol), molecules derived from phospholipids
c) Ca2+, from outside or intracellular stores

Term
CAMP as a messanger
Definition
the new enzyme makes CAMP with ATP and activates protein kinase A for cellular responses
Term
IP3 as second messenger
Definition
the enzyme activate by CAMP takes the substrate and releases parts into DAglucose and Ip3 and the IP3 diffuses and activates a ca2+ channel in the ER and lets CA2+ out for various proteins activated to cellular responses
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