UNIT 3 Flashcards
AOS 1 CH2
organic molecules
carbohydrates, lipids, nucleic acid, proteins, polysaccharides
inorganic molecules
oxygen and carbon dioxide, nitrogen, minerals
minerals
naturally occurring salts produced by weathering of rocks. e.g cofactors, magnesium, calcium, potassium, sodium ions
proteome
- complete set of proteins expressed by the genome
- varies between cell types, developmental stage and environmental conditions
- only specific genes are switched on
protein
an organic compound consisting of one or more long chains of amino acids connected by peptide bonds.
essential for structure and function of organisms
enzymes
- act as biological catalysts in metabolic reactions
- large globular structures that act within specific reactions to speed it up
proteome
- complete set of proteins expressed by the genome
- varies between cell types, developmental stage and environmental conditions
- only specific genes are switched on
protein
an organic compound consisting of one or more long chains of amino acids connected by peptide bonds.
essential for structure and function of organisms
enzymes
- act as biological catalysts in metabolic reactions
- large globular structures that act within specific reactions to speed it up
anabolic and catabolic reactions
A - reactions that make larger molecules
C - reactions that break down larger molecules into smaller molecules
amino acid structure
- amine group
- carboxyl group
- variable R group - the variable properties of the r group determine the type of protein the amino acid will form (hydrophobic, hydrophilic, polar, non polar)
polypeptide chains
- amino acids joined by peptide binds to form a chain
- backbone formed by carboxyl and amine groups, R group forms side chain
protein structure (4)
primary structure = linear sequence of amino acids
- can be different lengths
- shorter than 50 = peptide
secondary structure = folding or coiling of polypeptide chain by the formation of hydrogen bonds between carboxyl and amine groups
- alpha helix
- beta pleated sheet
- random coil
tertiary structure = polypeptides fold further to form more stable globular or fiborous 3D shapes
- disulphide bridge (sulphur bonds)
- hydrogen bridge
quaternary structure = 2 or more polypeptide chains creating a singular functional protein
fiborous vs globular protiens
F = insoluble, structural, elongated, little to no folding
- provide support and shape to the cell and are components of structural features such as membranes
G = soluble, compactly folded into spherical tertiary and quaternary structures
- enzymes and hormones
- catalytic, regulatory, motility proteins
protein secretory pathway - ribosomes and endoplasmic reticulum
- proteins for use synthesised in free ribosomes in nucleus
1. proteins for secretion synthesised by ribosomes on surface of rough endoplasmic reticulum
2. proteins travel through tubules and are modified
3. wrapped up in vesicle membranes and transported
protein secretory pathway - Golgi apparatus
= packages proteins into vesicles for export from the cell
1. transport vesicles Fues to Golgi at cis face
2. protein enters Golgi and moves between cisternae being progressively modified - sugar monomers are removed and substituted creating a variety of carbs
3. secretory vesicles come out of trans face and move to plasma membrane
protein secretory pathway - exocytosis
- membrane of vesicles and plasma membrane are the same allowing them to fuse
1. proteins alter the arrangement of phospholipids in bilayer allowing fusion of membranes
2. contents of secretory vesicle released from cell
3. vesicle membrane becomes permanent part of plasma membrane
endocytosis = pathway into cell
Denature and Renature
= when hydrogen bonds, disulfide bridges are broken and protein changes shape
= change to the active site
- irreversible once fully denatured
factors that effect protein function
temperature - increase and then denature at high temp due to breaking of bonds
ph - optimal range, if too high or low protein denatures or enzyme activity is decreased
concentration of ions or molecules acting as cofactors
AOS 1 CH3
nucleic acids
= organic biomolecules that store and transmit inherited characteristics of organisms
DNA = carries instructions to code for production of RNA, can self replicate
RNA = different forms w different functions
- read and translate DNA, cary a copy of a DNA sequence, protein synthesis
nucleotides
- phosphate group
- deoxy or ribose pentose sugar (5)
- nitrogenous base
- adenine and thymine (uracil)
- guanine and cytosine
purines = adenine and guanine
pyrimidines = cytosine, thymine and uracil
dna structure
rna structure
rna and dna comparison
eukaryote vs prokaryote
gene
= a region of DNA that may be translated into a polypeptide or RNA molecule that can be functional
- sequence of nucleotides within the genre contain the info for protein synthesis
genetic code
= a set of rules that defines how the info in nucleic acids is translated into proteins and functional RNA
- stored as 3 letter codes (triplets)
transcription and translation
Transcription = production of single stranded mRNA from DNA
- DNA triplet transcribed into mature mRNA forming codons
- start codon = AUG, initiates translation
- multiple stop codons, end translation
Translation = the sequence of an mRNA molecule is used to produce the amino acid sequence of a polypeptide
- polypeptide strand is formed from the codons coding for particular amino acids
the genetic code is…
universal - the same code is used for all life forms on earth
degenerate/redundant - multiple codons code for the same amino acid
structure of genes - promotor region
= an upstream binding region for the enzyme involved in the encoding process where transcription is initiated
- identifies which DNA strand will be transcribed, where transcription will begin, which direction transcription will occur
(RNA or DNA polymerase)
TATA box
exons and introns
E = coding segments (expressed), form mRNA which is translated into proteins
- directly code for a polypeptide or signal stop and start of translation
I = none coding segments that are spliced out (only in eukaryotes) of mRNA during RNA processing
- also found in tRNA and rRNA but use a different process
gene expression
= process of information stored in a gene being used to synthesise a functional gene product
1. transcription
2. RNA processing
3. translation
types of RNA - mRNA
messenger RNA
= formed in the nucleus by transcription
= caries a copy of DNA sequence for a protein
= formed my RNA polymerase
= converted into mature m RNA and binds to ribosome for translation
types of RNA - rRNA
ribosomal RNA
= synthesised in nucleus
= based on nucleotide sequence of DNA
= with proteins it forms ribosomes
ribosomes = site of mRNA translation into amino acids
types of RNA - tRNA
transfer RNA
= links between amino acids and mRNA
= have an anticodon, complementary to codons on mRNA
= have a binding site for an amino acid (freely attach in cytoplasm)
= tRNA with anticodon forms a complex with ribosome, tRNA is shifted to exit site where chain grows
where does gene expression occur
-transcription and RNA processing occur in the nucleus
- translation occurs in the cytoplasm
- transcription - initiation, elongation, termination
= DNA - mRNA
transcription unit = DNA segment
Initiation =
- transcription factors combine with promotor region
- RNA polymerase binds to the promotor region and unwinds and unzips DNA by breaking hydrogen bonds
Elongation =
- RNA polymerase covers 30 base pairs. a segment of 15 basepairs is uncoiled forming a transcription bubble
- as RNA p moves along gene DNA behind it is recoiled
- RNA produces a strand of complementary primary transcript mRNA as it reads the DNA. complementary nucleotides are attached to the DNA template strand to create the mRNA
- MRNA ALWAYS SYNTHESISED IN 5-3 DIRECTION WITH NUCLEOTIDES ADDED TO 3 END
Termination =
- RNA polymerase reaches the termination site of gene, stopping transcription
- a poly-A signal triggers proteins to cleave the mRNA
- DNA strands join back together (hydrogen bonds reform without need for additional enzymes)
what are the different DNA strands called
template strand = DNA that is transcribed into mRNA
coding strand = DNA that is complementary to the template strand
- mRNA is the same as the coding strand but has uracil in place of thymine
RNA processing (removal…)
splicing = introns are cut out of primary RNA transcript to form the mature mRNA molecule
spliceosome = complex molecule of protein and RNA
- removes the introns from the primary mRNA transcript and joins exons together
- not all exons will necessarily be included
- single-stranded mature mRNA exits nucleus via nuclear pore
alternative splicing
= primary transcript can be spliced in different ways, resulting in alternative mature mRNA strands from a single gene forming different proteins
- some exons are removed along w introns
- introns are essential as they contain nucleotide sequences needed for sliceosome to form and may have regulatory functions
- RNA processing (addition…)
- addition of 5 cap and poly-A-tail = increases stability and prevents degrading of primary mRNA transcript
5 cap/ methyl cap = methyl guanosine triphosphate molecule added to 5 end - aids in binding of ribosome to mRNA at beginning of translation
poly-A-tail = chain of up to 250 adenine nucleotides added to 3 end
- translation - initiation, elongation, termination
= codons on mRNA are translated into sequence of amino acids creating a polypeptide
Initiation
- small ribosomal subunit attaches to 5 END of mRNA and moves along to start codon AUG
- tRNA brings anticodon UAC and brings amino acid methionine to mRNA and then joins to the codon, attaching the complementary base pairs (amino acids attach to tRNA in cytoplasm, catalysed by enzymes)
- large ribosomal subunit attaches to tRNA and small unit forming an aminoacyl, peptide and exit site for tRNA
Elongation
- tRNA brings more complimentary anticodons and adds its specific amino acid to the polypeptide chain
- amino acid joins to first amino acid through condensation polymerisation reaction
ribosome releases tRNA and moves along mRNA
!! tRNA can be reused to pick up more amino acid !!
termination
- attaching of amino acids continues til stop codon
- polypeptide chain is released from ribosome into cytoplasm or endoplasmic reticulum
- proteins with more than one polypeptide form fully functional proteins in cytoplasm or Golgi apparatus
- polypeptides remain in cell or are exported (exocytosis)
!! many polypeptide strands can be formed at once
gene regulation
- gene expression is highly controlled and can be regulated at any stage
- during transcription in cytoplasm in prokaryotes (only have transcription and translation stages)
constitutive, regulatory, structural genes
C = always switched on and transcribed continually
R = code for transcription factors/repressor proteins that control gene expression during transcription
S = code for proteins and RNA, not involved in gene regulation
e.g enzymes, protein channels, protein components, tRNA
operons
= multiple structural genes transcribed together and controlled by a single promotor
- mostly prokaryotes
operon structure
promotor region = binding site of RNA polymerase
operator region = binding site of transcription factor
structural genes = code that is transcribed and translated into products needed
how operons work
- repressor proteins bind to the operation, preventing transcription of structural genes
repressor can be = - bound to operator most of time and removed to switch on/induce operon
- inactive most of time and activated when needed to switch off/repress operon
tryptophan
= an amino acid used to build proteins found where E.coli lives
- when in short supply prokaryotes produce their own using trp operon
trp operon
= a repressible operon that is switched on by default but can be turned off
= responsible for coding and regulating the production of tryptophan
- genes are transcribed into mRNA which form poly peptide subunits which make up enzymes that produce tryptophan
trp operon structure
promotor = RNA polymerase binds
operator = trp repressor binds
5 structural genes
trpR = regulatory gene that codes for transcription factor - trp repressor
- expressed constitutively so repressor is always present
- tryptophan acts as a corepressor to bind to repressor, changing its shape so it can bind to operator and block RNA polymerase from transcribing structural genes
when tryptophan is present vs not present
not present =
- trpR produces inactive trp repressor that can’t bind to operator
- RNA polymerase binds to promotor region and reads genes forming mRNA
- mRNA forms poly peptide subunits that make up enzymes for tryptophan synthesis
present =
- Tryp produces trp repressor
- tryptophan acts as a corepressor and binds to trp repressor, changing its shape
- the now active repressor binds to operator, blocking RNA polymerase from transcribing genes into mRNA
attenuation
- trp operon controlled by how much trp carrying tRNA is present
- interferes with translation of mRNA into amino acids to form tryptophan
High trp tRNA levels = operon not expressed - ribosome moves quickly so region 2 and 3 don’t have a chance to bind
- region 3 and 4 bind instead and issue termination signal causing the ribosome to fall off
Low trp tRNA levels = operon expressed - ribosome moves slowly allowing loop between region 2 and 3
- this blocks formation of repressor loop (3 and 4) allowing translation to continue
AOS 1 CH4
DNA amplification
= uses PCR to create a large quantity of DNA that is identical to the initial trace sample
- increases amount of target DNA so it is large enough to be used
(e.g blood from a crime scene)
target DNA
= a particular region of a DNA molecule that a scientist intends to study or manipulate
polymerase
= enzymes that catalyse the formation of long chain molecules (polymers, DNA or RNA) by linking smaller molecules (nucleotides)
= important role in replication, repair and maintenance of DNA
types of polymerase
RNA polymerase
DNA polymerase:
- taq polymerase
- reverse transcriptase
DNA polymerase
- PCR and DNA sequencing to synthesis multiple copies or target DNA
- adds complimentary nucleotides to create a new strand, complimentary to target DNA
RNA polymerase
- synthesise RNA from DNA during transcription
- attaches to promotor and unwinds DNA, adding nucleotides in 5-3 prime direction
- slower than DNA polymerase
- used to study transcription and RNA amplification
taq polymerase
= DNA polymerase commonly used in PCR
- heat resistant making it useful in DNA manipulation i.e PCR
- comes from bacteria thermos aquaticus
reverse transcriptase
= DNA polymerase that synthesises single stranded DNA using RNA as a template
- reverse of transcription (RNA-DNA)
- used to make complimentary DNA (cDNA) that has introns spliced out
- used to produce DNA that can be amplified by PCR
reverse transcriptase reading and transcripting direction
- reverse transcriptase reads mRNA in a 3-5 prime
- transcripts cDNA in a 5-3 prime
what direction does DNA polymerase go in
only in 5-3 prime direction
PCR
= polymerase chain reaction
= method of amplifying specific target sequences of DNA
- Taq polymerase (a DNA polymerase) is used as it is stable in high temperatures
- each cycle doubles the amount of DNA
- all DNA produced matches the target strand
PCR mixture
- DNA and target DNA being amplified
- free nucleotides (build new DNA strands)
- heat resistant DNA polymerase (Tan polymerase) (to elongate DNA strands by adding nucleotides
- 2 DNA primers compplimentary to ends of target DNA (specify the start and finish of DNA fragment being amplified) (synthetic, single stranded, >30 bps
PCR steps
- PCR mixture is placed in DNA thermocycler to alter temperature
1. Denaturation 95°C - sample heated to break hydrogen bonds of DNA into 2 single strands
2. Annealing 50-60°C - sample cooled so primers anneal/bind (form hydrogen bonds) to complementary sequences on opposite strands at either end of DNA sequence
3. Extension 72°C - sample heated so Taq polymerase attaches to primers and moves along adding free nucleotides to form double stranded DNA
(3 step process is repeated up to 50 times to ensure there is sufficient target DNA to work with)
Gel electrophoresis
= separating fragments of DNA (or RNA) in a sample based on size
- electric current is applied to Gell, negative charged DNA move through gel to positive terminal
- small DNA moves faster than large, separating based on size
applications of gel electrophoresis
- DNA screening i.e testing for inherited conditions
- confirming correct gene has been amplified in PCR
- identifying DNA fragments to be used for genetic engineering
Gel electrophoresis steps
- gel is prepared (composed of agarose/sugar, rectangular, jelly like with wells at one end)
- gel placed into gel electrophoresis chamber with wells at NEGATIVE terminal
- DNA samples loaded into wells in gel
- a DNA ladder/molecular weight standard/size standard containing DNA fragments of KNOWN LENGTHS is run for comparison (allows length of samples to be estimated)
- gel placed in a bath and covered with PH with ions to conduct electric current
- power source attached and turned on. electric current causes NEGATIVELY charged DNA fragments to migrate to POSITIVE terminal
- SMALLER fragments move FASTER and migrate FUTHER than large fragments
- DNA made visible by being stained with a fluorescent or methylene blue stain
fluorescent vs methylene blue stain
fluorescent - included in gel or added after, viewed with ultraviolet light
methylene blue - added after running gel, visualised by eye
DNA ladder
= contains DNA fragments of known lengths to compare to DNA samples and estimate length
how is gel electrophoresis measured
by base pairs (BP)
detecting mutations with PCR and Gel Electrophoresis
- by amplifying target gene w mutation and measuring base pairs of normal vs mutated gene
DNA profiling
= a technique that compares and identifies individuals based on their unique DNA sequence
- used in forensics
- identify perpetrator, bodies, genetic relation
polymorphisms/short tandem repeats (STRs)
= inherited variations in introns of individuals (non coding segments)
STRs = short repeated sections between 2-6 base pairs examined to find differences
- length of STRs can vary between homologous chromosomes
plasmids
= small, circular DNA molecules found in bacterial cells
- used as vectors to move target DNA from one organism to the other
- used in bacterial transformation
- has self replicating properties
vectors
= carriers
Restriction enzymes/endonucleases
= a large group of enzymes that occur naturally in bacteria and target foreign DNA that enter a cell and cut it into smaller fragments
- enable scientists to cut DNA into smaller, more usable fragments and isolate particular regions of interest e.g a single gene
- cuts, destroys and prevents DNA from replicating
- targets a specific sequence of nucleotides (4-6 bp in length) called a recognition site
- breaks phosphodiester backbone on DNA strand of recognition sites when it passes
recognition site
= a specific sequence of nucleotides 4-6 bp in length that the enzyme targets and cuts
bacteriophages
= viruses that infect bacteria that restriction enzymes would cut
sticky end restriction enzymes
= leaves DNA with overhanding ends
= cuts DNA backbone at different locations on each strand within the recognition site
- exposed bases are then able to form complementary bade pairs through hydrogen bonding with nucleotides of other DNA w sticky ends
blunt end restriction enzymes
= leave clean cut ends by cutting the sugar phosphate backbone on both strands at same location in recognition site
e.g HaeIII cuts between GGCC on both strands
palindromic sequence/sticky end enzyme example
= sequence on complimentary strand is same as other read backwards
e.g EcoRI from E.coli cuts at GAATTC and CTTAAG
ligase
= group of enzymes that join fragments of DNA and RNA (by creating phosphodiester bonds)
process = ligation
- RNA and DNA
DNA ligase
= join segments of newly replicated vDNA and repair brakes in DNA molecules
- can join fragments from different organisms/species as DNA is universally consistant
ligation or sticky ends
- specific because exposed bases bind to complimentary base pairing (attracted by weak hydrogen bonds)
- ligase creates phosphodiester bond between 3OH end and 5phosphate end of adjoining nucleotides
- makes recombinant DNA and used in gene cloning
ligation of blunt ends
- random
- any 2 fragments can join if they come in contact and DNA ligase joins them
- more difficult to use in DNA manipulation that requires joining of specific fragments
- sometimes unavoidable and needed to not damage gene
- can attach short segments of DNA to create sticky ends using ligase
clone
= genetically identical copy of a gene, cell or organism
recombinant DNA
= DNA from 2 different species joined together
- create to clone different genes
insulin
- for treatment of type 1 diabetes
- used to be extracted from animals (expensive and time consuming, risk of disease and allergic reaction)
- recombinant human insulin now used
recombinant plasmid
= plasmid containing a foreign gene that has been inserted using restriction enzymes and DNA ligase
why are plasmids used as vectors
- small so easy to manipulate in lab
- carry restriction enzymes
- self replicate independently in host bacterial cells at a fast rate
enable identification of cells with recombinant plasmids
- reporter gene
- antibiotic resistant gene
reporter gene
antibiotic resistant gene
creating recombinant DNA
complimentary DNA
regulatory genes in recombinant DNA
genetic transformation
bacterial competence
selection and screening of transformed bacteria
lacZ gene
artificial transformation of bacterial cells
issues and implications of recombinant DNA technology
GMO vs Transgenic organism
crisp-cas9
genetically modified plants
genetically modified animals
AOS 2 CH 5
AOS 2 CH6
AOS 2 CH7
natural selection (points to hit)
- Populations contain genetic variation that causes phenotypic variation
- Under different conditions some variants confer selective advantage which means that the individual has a greater chance of reproducing
- Their offspring will carry their parent’s alleles/genes leading to an increased prevalence of these alleles/genes in the next generation. Over time this will increase the allele’s frequency within the population leading to an increase in the phenotype within the population.
speciation (points to hit)
- What had caused reproductive isolation:
Allopatric: Geographic barriers (eg. Galapagos finches)
Sympatric: Breeding times, different niches (eg. Howe Island palms) - Why this leads to speciation: Natural selection and genetic drift cause the two populations to accumulate genetic differences until they can no longer successfully interbreed.
cellular respiration (3 steps)
- glycolysis (cytoplasm of cell)
- kreb cycle (mitochondrial matrix in mitochondria)
- electron transport chain (crustal/inner membrane of mitochondria)
biomass
- contains high sugar to produce ethanol
- through hydrolysis
ATP phosphorylation
= production of ATP
- occurs in all stages of cellular respiration
hydrolysis
= breakdown of chemicals by water
fermentation of ethanol (conditions required)
- low oxygen
presence of microorganisms
lymphatic system
- contains lymph nodes
- where lymphocytes r found
- innate and adaptive immune system meet
transformed bacteria
= has a recombinant plasmid
hominoid features
- no tails
which homo doesn’t fit the trend of increasing brain size
homo floreseinsis (has smaller brain than Australopithecus)
aneuploidy
= abnormal number of chromosomes
enzyme substrate interaction models - lock and key model
= substrate ‘key’ must fit the active site ‘lock’ in order to bind
enzyme substrate interaction models - induced fit model
= when substrate binds to active site a conformational change (change in shape) of active site occurs.
- accurate as active site is flexible and capable of chang to achieve a TIGHTER FIT
main features of enzymes
- specificity (different enzymes acts as catalysts for different biochemical reactions)
- catalytic power (make reactions occur more quickly)
what do enzymes do to activation energy
= reduce it as reaction requires less energy
- enzymes influence proximity and orientation, microenvironment and ions
photosynthesis stages
light dependent
- light energy to chemical energy (ATP)
light independent (Calvin cycle)
- chemical energy (ATP) to synthesise organic molecules (glucose)
cellular respiration
= releasing of energy from glucose to generate chemical energy (ATP)
photosynthesis equation`
carbon dioxide + water - glucose + oxygen + water
6CO2 + 12H2O - C6H12O6 + 6O2 + 6H2O
or 6CO2 + 6H2O - C6H12O6 + 6O2
cellular respiration equation
glucose + oxygen = carbon dioxide + water + energy ATP
C6H12O6 + 6O2 = 6CO2 + 6H2O + ATP
photosynthesis location and inputs and outputs
(in the chloroplasts)
light dependent (thylakoid membrane)
- NADP+ = NADPH
- ADP = ATP
light independent (stroma)
- ATP = ADP
- NADPH = NADP+
- CO2 = C6H12O6
coenzymes
= non protein molecules that assist enzyme activity
ORGANIC MOLECULES
- transfer protons, electrons or chemical groups from one molecule to another
- loaded = has something to donate
- unloaded = free to accept something
e.g ADP loaded w phosphate and NADP+ loaded with electrons
cofactors
= bind to enzyme before substrate to enable enzyme to catalyse reaction
- can be inorganic, if organic called coenzymes
energy
= required to break bonds, released when new ones are formed
factors that regulate enzyme activity
- temperature
- PH
- enzyme and substrate concentration
inhibition of enzyme activity (reversible vs irreversible)
reversible = weak bonds (hydrogen) and are easily broken
- temporary binding
- inhibitor and substrate in competition for enzyme
- increasing substrate concentration has effect on reaction rate
irreversible = strong bonds (covalent) and can’t be bond w/o breaking enzyme
- permanently disables enzyme
- increasing substrate concentration has no effect on reaction rate
inhibition of enzyme activity (competitive vs non competitive
competitive = shape of inhibitor similar to substrate and binds to active site, blocking substrate
non competitive = inhibitor binds to allosteric site (not the active site) changing the conformation (shape) of active site so substrate can’t bind
inhibition of enzyme activity (feedback inhibition)
= when a product produced late in a pathway is also an inhibitor of an enzyme earlier in the pathway
- as inhibition increases, number of enzymes being inhibited increases
- helps control enzyme activity
biochemical pathway
= series of chemical reactions that occur inside a cell
c3 plants
c4 plants
CAM plants
factors that affect photosynthesis
- light availability
- water availability
- temperature
- CO2 concentration
factors that affect photosynthesis
- light availability
- water availability
- temperature
- CO2 concentration
optimum rate
= where reactions occur at the fastest rate, below optimum reactions slow down
factors that affect cellular respiration
- temperature
- glucose availability
- oxygen concentration
antigens
= unique molecules recognised by receptors on T cells or antibodies produced by B cells
= allow body to recognise harmful pathogens and administer an immune response
immunogens
= antigens that elicit an immune response
antibodies
= proteins produced by B lymphocytes that bind to specific antigens
allergens
= antigens that result in immediate hypersensitivity reactions/allergic responses due to over activation of immune system to harmless antigens
self and non self antigens
non self =
self =
antigen structure
= one or more polypeptide chains or carbs, lipids of nucleic acids
leukocytes
= immune cells/ white blood cells that protect the body from foreign substances
types of immune cells
phagocytes
natural killer
eosinophils
macrophages
APCS
= antigen presenting cells
MHC 1 and 2 markers
cellular pathogens
- fungi, bacteria, protozoans, oomycytes, worms, arthropods
non cellular pathogens
- viroids, viruses, prions
innate immune system
physical barriers (innate)
plants
- well walls providing strength and flexibility
- cutin and waxy cuticle, thick cuticle
- thick bark
- closing of stomata
- orientation of leaves
animals
- intact skin/epithelial cells
- mucus secreting membranes
- cilia that sweep foreign bodies away
chemical barriers (innate)
plants
- alkaloids
- phenolics
- saponines
- terpenes
animals
- lysozymes in tears
- acid in sweat
- mucus
- stomach acid and gut microbiomes
- PH and antimicrobial proteins in genetics
adaptive immune system
cell mediated immunity
