POB Exam 2 Flashcards
Photosynthesis does what
Convert solar energy into chemical energy of a carbohydrate
Carbon dioxide enters the leaves through
Stomata
Filled interior of chloroplast is called
Stroma
Flattened sacs in chloroplast is what
Thylakoids
Thylakoids are stacked to form what
Grana
Chlorophyll and other pigments part of the thylakoid membrane do what
Absorb solar energy
Chloroplast has a what kind of membrane
A double membrane
Outer and inner membrane
Photosynthetic equation
6CO2 + 6H20 —
What are the two set of reactions in photosynthesis
Light reactions (dependent of light)
Calvin cycle (independent of light)
Electromagnetic spectrum
Gamma ray—
What are the photosynthetic pigments
Chlorophyll a and b
Carotenoids
Each of them absorb a specific wavelength
Leaves appear green because what light is reflected
Green
All other colors absorbed, reason we see a color is because it is reflected off
Light reaction of photosynthesis contains what process
Photosystem 2
Electron transport chain
Photosystem 1
Where does the light reactions take place
Thylakoid membrane
Ps2 does what?
Pigment complex absorbs solar energy
—>
Energy passes from on pigment to
another until reaching reaction center —>
Electrons energized
(Electron acceptor)
Water is split to replace energized electrons —
At the electron transport chain what happens
Carries energy from ps2 to ps1
Energy is release to pump hydrogen ions into the thylakoid space forming a gradient
When the ions flow through atp synthase it forms ATP
PS1 does what
Absorbs solar energy
Low energy ps2 electrons used to replace those lost in ps1
Adjacent to enzyme that reduces NADP+ to NADPH
(Accept electrons from ps2 to do this)
Hoover dam = light reaction
Reservoir = thylakoid space bc it store something
Rain water (light from sun)
Hills that collect water (Ps2 and ps1)
Water kept inside reservoir - hydrogen ions
Water released that power turbine (atp synthase) energy is formed (atp)
Where do plants get their carbon to grow their tissue
Inorganic carbon through leaves
Calvin cycle purpose is to do what
Use co2 to produce carbohydrate for plant
Where does the Calvin cycle take place
Stroma
Calvin cycle has three steps what are they
Co2 fixation
Co2 reduction
Regeneration of RuBP
Co2 reduction does what
It reduces Co2
Co2 becomes CH20
Possible by energy and electrons supplied by ATP and NADPH from light reactions
Regeneration of RuBP does what
Reforms RuBP by
Going through the cycle 3 times allows G3P exit, which uses 5 of them for 3 cycle
Creating RuBP
Why is the Calvin cycle important
G3P ca be used to for many other molecules like
Fatty acid and glycerol for plant oil
Glucose
Fructose
Starch and cellulose
Photosynthesis vs cellular respiration
Both use cellular respiration
Mitochondria
Break down glucose
O2 to co2
Only plants do photosynthesis
Chloroplast
Build glucose
Co2 to o2
Both use electron transport chain and chemiosmosis to produce ATP
DNA and RNA are polymers of what
Nucleotides
They are polymers (nucleic acids) of monomers (nucleotides)
DNA nucleotides have 4 nitrogenous bases
Adenine
Thymine
Cytosine
Guanine
DNA vs RNA
DNA deoxyribonucleic acid
RNA Ribonucleic acid
Uses ribose instead of deoxyribose
Uracil instead of thymine
Single strand
Who discovered dna
James Watson and Francis crick worked out 3D structure of DNA based off of Rosalind Franklin
Double helix is dna structure
DNA structure
Double helix
Held by hydrogen bond
At
CG
DNA replication does what basically
DNA to DNA (identical to parent strand)
It is semi conservative
Old strand makes new strand
DNA helicase
Breaks unzip dna strand
DNA polymerase
Puts new strand of dna together
DNA ligase seal any breaks in sugar phosphate backbone
Gene expression is the process
Of using gene sequence to synthesize a protein
How many process is inside gene expression
Transcription
Translation
Transcription
Take place in nucleus
DNA to RNA
DNA serves as template for mRNA formation
Uses RNA Polymerase to create mRNA
starts transcribing when there is a certain nucleotide sequence called promoter
Terminator tells it to stop transcribing
Genetic code
Triplet code - each three nucleotide unit of mRNA molecule is a codon
mRNA codons
There are 64 different mRNA Codons
61 code for particular amino acids
Redundant code - codes of some amino acid have numerous code words
Protect against mutation
Co2 fixation has what happening
Co2 is attached to 5 carbon RuBP molecule
Happens 3 times
Results in 6Carbon molecule splits into two 3 carbon molecules
Done by RuBP carboxylase (stroma is full of this
Translation has 3 parts what are they
Initiation (needs energy)
Elongation (need energy)
Termination
Translation: initiation
Brings ribosome components together
Small ribosome sub unit
mRNA
Initiator tRNA (attach to start codon AUG)
Large ribosomal subunit
3 binding site for tRNA
P (peptide) site
A (amino acid) site
E (exit) site
Translation: elongation
Process by which polypeptide increases in length
Steps in elongation
tRNA approaches A site (A tRNA w attached peptide is at P site)
tRNA binds to A site
Peptide bond forms to attach the new amino acid to the peptide chain
Ribosome moves forward, empty tRNA exits the E site and tRNA carries new amino acid to the ribosome
Translation: termination
Termination occurs at the stop codon
Causes formation of 2 ribosomal subunits
What are the differences btw introns and Exons
Introns are removed
Exons are used bc they have DNA that can make protein
They are the expressed portion of genes
Gene mutations are what
Permanent change in the sequence of bases in dna
What causes gene mutations
Error in replication
Mutagens
Transposons
Viruses
Error in replication
DNA replication errors are rare for mutation source
Bc DNA polymerase proof reads to catch error
Mutagens are what
Environmental influences that can cause mutation
DNA repairs enzyme constantly to monitor and repair
Transposons are what
Specific DNA sequences that move within or between chromosomes
(Weird occurrence were they get cut and spliced and out at diff spots)
Viruses can do what to cause mutagen
They insert their dna into host chromosome
Can cause HPV - leads to cervical cancer
3 type of point mutations are
Substitution
May change specific amino acid (change a nucleotide)
Insertion (frameshift)
Insert nucleotide
Deletion (frameshift)
Delete nucleotide
Silent mutation
May have no affect (change amino acid but no affect)
Frame shift mutations are what
One or more nucleotide are either inserted into or deleted from dna
Results in new sequence of codons and nonfunctional proteins
The inability to breakdown phenylalanine results in what
PKU
Mental impairment
The inability to convert tyrosine to melanin results in what causes condition
Albinism
Translation is
Occurs in cytoplasm
RNA to protein
Coordinated by ribosomes
Anticodons on the tRNA recognize the appropriate codon on the mRNA
Codes for certain amino acid
The stages of the cell cycle are
Interphase
- G1
- S
- G2
Mitotic
- Mitosis
- Cytokinesis
The cell cycle deals with what kind of cells and for what reason
Somatic cells (body cells)
For creation of new cells for reproduction
Growth
Repair
Replacement
Apoptosis is what
Programmed cell death (to decrease # of cell)
Ex)
- caterpillar to butterfly
- tail of tadpole
- webbing be human finger and toes
- destroy bad cell (prevent cancer)
Stages of interphase
G1 (checkpoint)
- cell growth before synthesis of dna
- if dna damaged go to apoptosis or go to G0 such in nerve or muscle cells
S (DNA synthesis)
DNA replication so that each chromosome contain 2 sister chromatids
G2 (checkpoint)
- cell growth
- cell synthesizes proteins for cell division
- if dna damaged go to apoptosis
Mitosis does what
Separation of sister chromatids and results into two daughter cells each containing complete identical set of chromosome and
Mitosis
Division of nucleus’s that follows interphase
Cytokinesis
Division of cytoplasm after mitosis
Chromosome numbers
Diploid (2n) cell have two of each number of chromosome
- 46 chromosome (2 pair of 23) = body cell
Haploid (n) cell have half the diploid number of chromosome
- human egg or sperm = 23 (1 pair)
If parent cell has a diploid of 14, how many chromosome will each New daughter have after mitosis
14
Bc dna replication produces duplicated chromosomes
Daughter cell same a parent
Stages in mitosis
Prophase - centrioles form, chromosome condense, nuclear envelope disappear
Metaphase- Line up at middle, spindle fibers attach to sister chromatids
Anaphase- sister chromatids pull apart
Telephase- nuclear envelope forms, Chromatid to chromatin
Cytokinesis- cleavage furrow, cytoplasm split
PMAT-C
What are kinetochores
Group of motor proteins that pull chromosomes along
Cytokinesis in animal vs plant
Animal
-splitting of cytoplasm (cleavage furrow)
Plant
- incomplete separation
- form cell plate between
What do proto oncogenes do
They are the gas peddle
They promote the cell cycle (prevent apoptosis)
Divide
RAS protein
Promote cell division
Normally must receive signal to initiate
Mutated always initiate
What do tumor suppressor genes do
They are brakes
They stop cell cycle
No divide
P53
Transcription factor that controls gene for cell cycle inhibitor
What is crossing over and when does it take place
It is the exchange of genetic material between non sister chromatids
It happens during prophase 1 of meiosis 1 (1st thing to happen)
What is independent assortment and when does it happen
Homologous pairs line up randomly and they split into non distinct pairs
Occurs at metaphase (line up) and splits at anaphase during meiosis 1
Homologous chromosomes are match in
Same length
Same centrosome position
Same gene location
Homologous chromosomes separate during what phase of meiosis
Anaphase 1
When do sister chromatids spectate in what phase
Anaphase (in mitosis)
Meiosis 2 (anaphase 2)
In what organ does meiosis take place in humans
In sex organs (reproductive organs)
What happens during fertilization
Gametes (haploid) fuse to from zygote and diploid number is restored
Mitosis is most like what
Meiosis 2
Mitosis vs meiosis
# divisions Mitosis has 1 meiosis has 2
Results in Mi(2 diploid cell) in Me 4(haploid cell)
Occurs inside: Mi(somatic cell) Me(reproductive cell)
Genetically identical: Mi(yes) Me(No)
When does it occur: Mi(all the time) Me(certain time for reproduction)
Role in body: Mi(repair, cell growth) Me(reproduction)
Cancer cells can survive and proliferate elsewhere in body due to
Moving to other tissue by vessels know as metastasis
Angiogenesis is new blood vessels growing into the tumor
- give it oxygen- deprive surrounding tissue
Genetics
Study of patterns of inheritance of trait
Mendel studying inheritance of traits through
Pea plants
Law of segregation
Each parent has Two factors (allele) for each trait
-diploid
Factors separate during formation of gamete
Each gamete only contains one factor
-haploid
Fertilization gives new individual two factors for each trait
Phenotype
What you look like
Genotype
Alleles carries by chromosome responsible for given trait
Dominant allele refers to what
Capital letter
Allele that will mask the expression of the recessive trait (lower case letter)
Dominant gene will show the phenotype
Breeding of homologous dominant and homologous recessive
PP (purple) x pp (white)
F1 (all will have same genotype bc Pp = purple)
F2 will have (3/4) purple (1/4) white
PP, 2Pp, pp
Homozygous
Two alleles same
Heterozygous
One dom
One recessive
Pressence of freckles
Dominant (F) Freckles
Recessive (f) no freckles
Mono hybrid cross is what
Cross of single gene
Heterozygous cross
Ff x Ff
Genotypic ratio:
1: 3 homo D 2:2 hetero 1:3 Homo Res
1: 2:1
Phenotypic ratio
3:1 freckles 1:3 none
Gentetic different be pure bred and mutt is likely that mitts are
Heterozygous for more allele
Test cross is a cross of
Cross bw dominant phentyoe and recessive phentype to find out genotypes of the one you don’t know
Ex if offspring with recessive is phenotype produced then dom parent must be hetero
Dihybrid cross
9:3:3:1 phenotypic ratio if heterozygous crosses
Cross of two traits
Ex)brown hair and long fingers
Dihybrid cross of heterozygous give phenotypic ratio of
9:3:3:1
Law of segregation states that what
Each gamete gets only one letter (allele) of each kind
Law of independent assortment states what?
That all combinations of alleles are possible
Autosomal recessive disorders are
Disorders linked to the recessive gene
If Hr X Hr
Then offspring will be affected
Equal chance for both sex
You have if you are homozygous recessive
Carrier if heterozygous
What is cystic fibrosis
It is when the chloride ions channel is defective due to a mutation
Causes abnormal thick mucus in bronchiol tubes of pancreatic ducts
This is due to no osmosis being able to be done
Autosomal dominant disorders are
Causes by the dominant gene
If parents are heterozygous some of the offspring will not have affect
Fatal familial insomnia what is it
It is a prison disease of the brain
Caused by misfolding of protein
Incomplete dominance is what
Both traits are co expressed
Ex) curly hair
Flamilial hyper cholesterol emia
Blood
Skin color
Blood toys ABO
IAi IAIA = A
IBi IBIB = B
IAIB = AB
ii = O
Polygenic inheritance is what
Is a trait controlled by two or more genes
Dominant genes are additive
Ex) skin color and height
How does environment affect gene expression
Temperature of eggs of crocodiles determine sex
Temperature affects himilyan rabbit color marking
Are freckles a dominant trait
Yes
BRCA gene
Deals with breast cancer
It is a tumor suppressor gene (promotes apoptosis)
Flamilial hyper cholesterol emia is What
High cholesterol in your blood due to bad receptor proteins bc receptors don’t bring cholesterol from blood for processing
Homozygous dominant normal
Heterozygous get mild
Homozygous recessive get very bad
What is Down syndrome?
It is caused when you have an extra chromosome in 21
Tis a trisomy on the 21 set
As you get older and try to have kids your chances of having a kid with what increases
Down syndrome
What are sex linked genes
Genes that a controlled by the X Y chromosome
Most sex linked defects are caused by the What chromosome
X
What two chromosomes make you female
Xx
What two chromosomes make you male
XY
Male humans get there X chromosome from their
Mother
Most x linked genetic disorders are what for females
Recessive
Reason makes get the sex links disorder often
Makes only have one allele (so whatever is on that allele determines the phenotype
What are some examples of x linked recessive disorders
Red green colorblindess
Duchenne muscular dystrophy
Hemophilia
Change in chromosome number is due to what
Nondisjunction
What is a trisomy
Chromosome is present in 3 copies
What is a monosomy
Chromosome is present in one copy
Which are more tolerable trisomies or monosomies
Trisomy
Why might girls born with abnormal numbers of X chromosome be able to survive
Extra X chromosome turns into a bar body
What is Turner syndrome
They are females with one X chromosome
Triplo x female
Have more x
Chromosome about 3
What is polyploidy
It is when errors in mitosis or meiosis produce species with more Than two chromosome sets
Xeroderma pignentosum Xp
Genetic disease in which the enzyme that are needed to repair dna damage due to Uv light are defective
