Unit 2 Flashcards
What is the order of intermediates of the Calvin Cycle?
RuBP (5C sugar) - PGA - G3P - Glucose
What do C4 AND CAM plants have in common?
they both use PEPC to do initial carbon fixation
What are two products of the light reaction phase?
ATP and NADPH
A pigment is a compound that
absorbs certain wavelengths of light
Where does the Calvin Cycle take place in?
chloroplast stroma
Why do cells communicate?
- coordinate activities
- organism development
- reproduction
- defense (immune system)
What is yeast?
a single-celled fungi
What is a quorum sensing?
bacteria can sense when population has become a critical number, and then the bacteria can coordinate certain functions
ex: bio-luminescent, toxin production in pathogenic bacteria, biofilm formation
How does quorum sensing work in biolumenecent squid?
auto-inducers are produced by bacteria, when levels of auto-inducers are too high, bacterial membrane picks up on it and turns on gene to generate light
What is local signaling?
cells in close contact
cell secrete signals and target cells
paracrine: cell produces signals, signals leave cell through secretory vessels, diffuse, then come into contact with target cells
synaptic: nervous system, gap between nerve cells called synapse, cell of nervous system sends neurotransmitters to target cells
What is long-distance signaling?
usually involves hormones,
endocrine signaling
hormones travel through bloodstream to specific targets
What is direct contact cell communication?
- signals can go between gap junctions between animal cells
- signals can go between plasmodesmata between plant cells
- cell-to-cell (like immune system) cells can physically recognize by bonding/contacting
What is the role of transmembrane proteins (plasma membrane)?
bond to signal molecules (ligand)
help carry signal response
What are the three stages of cell signaling?
Reception - Transduction - Response
What is the reception stage of cell signaling?
bonding of ligand to receptor, often in membrane (sometimes in cell),
when binds changes shape of receptor protein so protein can react with other proteins in the cell
What is the transduction stage of cell signaling?
signal is relayed within cell, interaction between receptor protein and other molecules, can be amplified by cascade reaction (signal gets multiplied)
What is the response stage of cell signaling?
activation of cellular response
Where are receptors located?
in target cells
What is GPCR cell signaling?
G protein coupled receptor
GPCR resides in plasma membrane, interacts with G-protein, G-protein is able to bind to GDP or GTP (similar to ATP) molecules,
inactive: G protein bound to GDP
when receptor is active by binding ligand, it change shape to interact with G protein
G protein binds with GTP, provides energy to activate enzyme - cellular response
after, GTP is hydrolized (loses phosphate) and becomes GDP
(G-protein bound with GTP activates another protein(enzyme))
What is Tyrosine Kinases cell signaling?
receptor is also an enzyme
tyrosine - amino acid that can receive phosphate group
kinases - enzymes capable of transferring phosphate groups from ATP to other molecules
ligand binds with monomer receptor tyrosine, two halves of tyrosine come together and are now a dimer. they are also now active
activated kinase enzyme transfers phosphate groups from 6 ATP to tyrosine parts of a protein
active receptor transfer phosphate groups to relay proteins - then cellular response(s)
What is the equation for photosynthesis?
6CO2 + 6H2O → C6H12O6 + 6O2
What are the products of photosynthesis?
Oxygen and glucose
What is reduced in photosynthesis?
CO2
What is oxidized in photosynthesis?
H20
What is light dependent reactions?
Photosynthesis I and II, needs light
What is light independent reactions?
Calvin Cycle, does not need light to operate
What is the visible spectrum?
light you can see
What pigments are used in photosynthesis?
chlorophyll and cartenoids
What wavelengths of light are used in photosynthesis?
violet-blue and orange-red
What determines the wavelength’s strength?
shorter wavelengths have more energy
What part of a plant allows CO2 to enter?
stomata
What is the electron carrier in photosynthesis?
NADP+, becomes NADPH (reduces CO2)
Where are photosynthesis pigments located?
in the thylakoids of plants
What was Engelman’s experiment?
used spectrum of light to determine what algae used in photosynthesis
What are the two types of chlorophylls?
chlorophyll a (blueish green) reaction center (does most of the work)
and chlorophyll b (yellowish green)
What is the the structure of chlorophyll?
porphyrin ring: light absorbing head of chlorophyll with magnesium atom center
hydrocarbon tail
What is photosystem I?
reaction center P700
electron transport chain from photosystem II
two products: NADH and ATP
What is photosystem II?
reaction center P680
absorbs light then goes into high energy state
goes through electron transport chain
What is the equation of the Calvin Cycle?
6CO2 + 12NADPH + 18ATP –> 1 hexose + 18ADP + 12NADP+
What are the phases of the Calvin Cycle?
- Carbon reduction
5C sugar, RuBP - PGA - Reduction
G3P - glucose output - Regeneration of RuBP
G3P back into RuBP
What are types of pigments?
Cartenoids (absorb blue, accessory pigments)
carotene (orange)
xanthophyll (yellow)
What is excitation by light?
fluorescence
What are the two phases(?) of photosynthesis besides Calvin Cycle?
hill reactions (make ATP) and sugar building (in stroma)
Where is ATP made in photosynthesis?
thylakoid by chemiosis
What are the products of the Calvin Cycle?
ADP and NADP+
What are the 5 phases of mitosis?
Prophase, Prometaphase, Metaphase, Anaphase, Telophase
What are the 3 stages of cell communication?
signal reception - transduction (signal relayed) - response
When do CAM plants absorb CO2?
the stomata open at night
What happens during metaphase?
chromosomes line up on cell plate, spindle fibers attatch
What happens during prometaphase?
chromatins thicken, nuclear envelope disintegrates, spindle starts
What happens during anaphase?
chromosomes are pulled apart by spindle
What are gap junctions?
channels that allow for intercellular connection and the passage of ions and small molecules
How are gap junctions made?
hemichannels that are composed of connexins
Where do hemichannels reside?
In the outer layer of the cell membrane so that they can connect to hemichannels of other cells
What is the structure of a hemichannel?
6 connexin proteins
Where are connexins made?
in the ER
Gap junction flowchart:
ER makes connexins - connexins go to golgi apparatus - 6 connexins form one hemichannel - vesicles deliver hemichannel to cell membrane - hemichannel diffuses through the membrane - arrives at a gap junction, can connect with neighboring hemichannels/cells - lysosomes break off old parts and replace with newer ones - lysosomes break down proteins into amino acids that get released into cytoplasm
What is a cleavage furrow?
the pinching of the cytoplasm to separate into two cells, in animal cells
What prevents mutations in cell division?
checkpoints
What is the centromere?
attachment points of chromatids
What is chiasma?
crossing of chromosomes
What is a centriole?
2 organelles that compose each centrosome in mitosis
What is the centrosome?
2 centrioles that helps organize the spindle
What is an allele?
different versions of a same gene
When does crossing over happen in cell division?
meiosis in prophase I, sections of sister chromatids are exchanged with each other
What is a diploid?
having pairs of chromosomes
What is a haploid?
having only one of each chromosome
What are gametes?
sex cells, egg and sperm
What is cytokinesis?
division of the cytoplasm
What is a gene?
sequence of DNA that codes for a protein
What is transcription?
from DNA to RNA
What is translation?
from RNA to proteins
What are homologous chromosomes?
chromosomes in pairs
What is a homolog?
the chromosome pair
What is interphase?
mitosis, period of growth
What is meiosis?
cell division that creates gametes