After Midterm Flashcards
A biologist ground up some plant cells and then centrifuged the mixture. She obtained some organelles from the pellet in the test tube that took up CO2 and gave off 02. The organelles are most likely
Chlorplasts
The pigments that absorb light energy to drive photosynthese is/are
Chlorophyll and carotenoids
The product of photosynthesis are
glucose and oxygen
Specifically, molecules of chlorophyll are located in membranes of sacs called
Thylakoids
All of the following compounds are required at some state of green plant photosynthesis except…
oxygen
Where do the 02 released during photosynthesis come from?
H20
What is the sequence that accurately reflects the flow of electrons in photosynthesis?
H20-Photosystem II-Photosystem I-NADP
Which of the following is true about the light-dependent reactions?
Photosystem II generates ATP, while Photosystem I generates NADPH
If C4 photosynthesis prevents photorespriration, why haven’t all plants evolved to use C4 pathways?
C4 is not advantageous to all climates
The correct structure of a DNA nucleotide is
Phosphate-5 carbon sugar-nitrogen base
T/F: In Semiconservative replication a DNA molecule serves as a template for a new DNA molecule which either consists of both parental strands of DNA or both newly synthesized strands of DNA
False
During DNA replication the lagging strand synthesizes DNA discontinuously forming ______________ which are later connected by ____________.
Okazaki Fragments/DNA ligase
What is the difference between free and attached ribosomes?
Free ribosome are in the cytoplasm while attached ribosomes are anchored to the endoplasmic reticulum. Free ribosomes produce proteins that remain in the cytosol while attached ribosomes produce proteins that may be exported from the cell
What is the interaction between the ER, ribosomes, and Golgi bodies in the export of protein from the cell?
Ribosomes manufacture proteins which travel through the ER to be packaged by the Golgi bodies for export
If the sequence of bases in a section of DNA is TAGGCTAA, what is the corresponding sequence of bases in mRNA?
AUCCGAUU
The function of the promoter is
to signal the RNA polymerase where to start transcribing the DNA, to signal the RNA polymerase which strand of DNA to read
Transcription is the process of
synthesizing an RNA molecule using a DNA template
T/F: The process of daughter synthesis in DNA, and mRNA synthesis is always proceeded in the 5 to 3 direction.
True
Photosynthesis is a ___________ process over all
a Endergonic process
What is the enzyme needed for photosynthesis
rubisco
Photosystem II generates ____________ while photosystem I generates _____________.
ATP/NADPH
Light dependent reactions
captured by pigments in chloroplast; in the thykloid membrane; uses water to keep flow of electrons going
Light independent reactions
Can take place at night, not energy harvesting, captures CO2 (anabolism)
Fredic Griffith
Vacine for phmona; discovered that even after viruses were dead their DNA could still be harvested
M. Williams & R. Franklin
used x-rays to look at chromosomes: found a chromosome was long & thin and uniform, DNA was helical, repressing subuints
Watson & Crick
Provided theory for structure of DNA
Purines
A&C: Dual rings (always bonds with single rings)
Pyrimadines
T&G: Single rings always bind with double)
Anti-Parallel fashion:
Each side of the later of DNA was 5’ to 3’ bases
DNA replication
Needs: parental strand, free nucleotides and variety of enzymes to unwind and synthesize new strands
DNA Gyrase:
Unwinds the parental strand of DNA
DNA Polymerase
Synthesizes new DNA: moves along each separate rung matching the old parental strand with complementary bases; polymerase always moves away from 3 (OH and free sugar) end to 5 (free phosphate) end. 3 to 5 on the daughter strand
3’ end
has free nucleotide, or hydroxyl group (OH)
5’ end
free phosphate and nucleotide
DNA Helicase:
Separates parental strands, breaks hydrogen bonds, creates replication bubble, one fork at each end
DNA Ligase:
Sews together missing pieces, ties DNA together
Order of replications
Gyrase-Helicase-RNA primase-DNA Polymerase-RNA Exonuclase-DNA Polymerase-Ligase
Translocation
One chunk of DNA is removed and placed somewhere else
Inversion
DNA segment is flipped around
RNA Primase:
Only can synthesize strands of DNA
RNA Exonuclase:
an co-enzyme with polymerse
Okazaki Fragments
short newly formed DNA fragments on the lagging strand
Synthesis of leading strand:
Priming: Primase
Elongation: DNA polymerase
Replacement of RNA primer by DNA: Polymerase
Synthesis of lagging strand:
Priming for Okazaki Fragments: Primase
Elongation: DNA polymerase
Replacement of RNA: Lygase
Telomeres
proof read and repair/used to insure 3-5 ratio is kept
rRNA
Ribosomal RNA: Combines with proteins to form ribosomes
mRNA
Messenger RNA: The base sequences care the information to create amino acid sequencing of proteins, each is three nucleotide bases wide called a codon, which represent different amino acids. Also, bind things together into an amino acid squence which creates proteins.
tRNA
Transfer RNA: carries specific amino acids to a ribosome during protein synthesis
3 differences between RNA and DNA:
- RNA is usually single stranded 2. It has sugar ribose backbone instead of a deoxyribose backbone 3. Uses Uricil instead of thymine
How many enzymes in the cytoplasms?
20 enzymes in the cytoplasm, one for each amino acid
translation:
Means to convert information from nucleotide language into amino acid language of proteins
Phenotypes
Where mutations are expressed
Spontaneous Mutations
random changes due to errors w/ known cases
Point mutations
addition, deletion, or substitution
Missense mutation:
Causes change in single amino acid
Nonsense mutation
changes normal codon from stop codon
Silent mutation
alters a base but does not change the amino acid
