Chapter 7 Flashcards
physiology
study of vital life processes of organisms
microbial physiology
- concerns vital life processes of microorganisms
- learn about human cells by studying bacterias nutritional needs, metabolic pathway, and why they live, grow, multiply, or die under certain conditions
- bacteria, fungi, and viruses are used in genetic studies because they produce generation after generation so rapidly
6 major chemical elements of all living protoplasms
- carbon, hydrogen, O2, nitrogen, phosphorus, and sulfur
- these can combine with other elements to make up vital macromolecules like carbs, lipids, proteins, and nucleic acids
essential nutrients
- materials that organisms are unable to synthesize, but are required for building macromolecules and sustaining life
- have to get these from environment/food
- essential amino acids, essential fatty acids
terms relating to an organisms energy source
- phototroph
- chemotroph
- chemolithotrophs
- chemoorganotrophs
phototrophs
use light as energy source
chemotrophs
use either organic or inorganic chemicals as energy source
chemolithotrophs
use inorganic chemicals as energy source
chemoorganotrophs
use organic chemicals as energy source
terms relating to an organisms carbon source
- autotrophs
- heterotrophs
autotrophs
use CO2 as sole source of carbon
heterotrophs
use organic compounds other than CO2 as carbon source
terms that combine energy and carbon source
- photoautotrophs
- phototheterotrophs
- chemoautotrophs
- chemoheterotrophs
photoautotrophs
use light as energy source and CO2 as carbon source
photoheterotrophs
use light as energy source and organic compounds other than CO2 as carbon source
chemoautotrophs
use chemical as energy source and CO2 as carbon source
chemoheterotrophs
use chemicals as energy source and organic compounds other than CO2 as carbon source
ecology
study of interactions between living organisms and the world around them
ecosystem
- interaction between living organisms and their nonliving environment
- interrelationships among different nutritional types are prime importance to ecosystem function
- ex: phototrophs like algae/plants are the producers of food and O2 for chemoheterotrophs like animals
endoenzymes
- enzymes produced within a cell that remain within the cell to catalyze reactions
- ex: digestive enzymes within phagocytes
exoenzymes
- enzymes produced within a cell and then released outside of the cell to catalyze extracellular reactions
- ex: cellulase and pectinase secreted by saprophytic fungi bread down cellulose and pectin
metabolism
- all chemical reactions that occur in a cell
- the chemical reactions are referred to as metabolic reactions
metabolic enzymes
enzymes that enhance and regulate metabolic reactions
- ex: hydrolases and polymerases
biologic catalysts
- enzymes are biologic catalysts
- proteins that either cause or accelerate a chemical reactions
- enzymes only catalyze one particular chemical reaction
- an enzyme can exert its effect only on one substance
- unique 3 dimensional enzyme shape allows it to fit into substrate like lock and key
- enzyme does not become altered during chemical reaction catalysts but it does not last forever
substrate
the particular substance the enzyme is catalyzing
factors that affect efficiency/effectiveness of enzymes
- each enzyme has optimum ranges of pH, temperature, and concentration (of enzyme or substrate)
- presence of inhibitors can also affect efficiency like heavy metals like lead, zinc, mercury, and arsenic
metabolite
- any molecule that is a nutrient, an intermediary product, or an end product in a metabolic reactions
2 categories of metabolic reactions
- catabolism
- anabolism
catabolism
- all catabolic reactions in a cell
- breaking down larger molecules into smaller molecules
- produces energy
anabolism
- aka biosynthetic reactions
- all anabolic reactions in a cell
- smaller molecules being put together to form larger molecules
- requires the use of energy
adenosine triphosphate (ATP)
- energy can be temporarily stored in high-energy bonds in special molecules
- ATP molecules are major energy storing/carrying molecules in a cell
- found in all cells because they are used to transfer energy from energy yielding molecules to energy requiring reactions
ATP and ADP and AMP
- when ATP is used as energy source it is hydrolyzed to adenosine diphosphate (ADP)
- ADP can be used as an energy source by hydrolysis to adenosine monophosphate
- ATP gives away one phosphate, break in bond gives energy, results in ADP. ADP gives away one phosphate, break in bond gives energy, results in AMP.
- can regain phosphate to return to earlier steps in cycle
energy and metabolism
- energy is required for metabolic pathways, growth, reproduction, sporulation, and movement of the organism and active transport of substances across membrane
- some organisms use energy for bioluminescence
- cellular mechanisms that release small amounts of energy as cell needs it usually involve a sequence of anabolic and catabolic reactions
biochemical pathways
- series of linked biochemical reactions occurring in a stepwise manner
- from starting material to end product
- nutrients are energy source and chemical bonds are stored energy
- glucose catabolization
2 ways to catabolize glucose
1) aerobic respiration
2) fermentation
biochemical pathway steps
- enzyme 1 acts on A to make B
- enzyme 2 acts on B to make C
- enzyme 3 acts on C to make D
- D is end product
- letters are substrates
catabolism of glucose my aerobic respiration 3 phases
1) glycolysis - anaerobic
2) The Krebs cycle - aerobic
3) the electron transport chain - aerobic
glycolysis
- glycolic pathway/Embden-Meyerhof pathway
- breakdown of glucose
- 9 steps each requiring specific enzyme
- uses 2 ATP and produces 2 ATP and NADH
the Krebs cycle
- citric acid cycle/tricarboxylic acid cycle/TAC cycle
- 8 reactions each controlled by different enzyme
- produces 2 ATP but also NADH, H+, FADH which enter electron transport chain
- oxaloacentate is end product
- produces CO2 3 times and H+ 5 times
site of Krebs cycle and electron transport chain in eukaryotes and prokaryotes
- in eukaryotes they occur in mitochondria
- in prokaryotes they occur at inner surface of cell membrane
electron transport chain
- electron transport system/respiratory chain
- series of oxidation-reduction reacts
- many enzymes involved
- cytochrome oxidase in one enzyme that transfers electrons to oxygen which is the final acceptor
- large number of ATP molecules are produced by oxidative phosphorylation
- produces 34 ATP in eukaryotes and 32-34 in prokaryotes depending on number of NADH produced during glycolysis that enter the mitochondria
fermentation of glucose
- does not involve O2
- first step is glycolysis
- second step is conversion of pyretic acid into an end product which can vary (ex: end product of yeast is ethanol for beer and wine)
- produce very little energy and is not efficient only about 2 ATP
oxidation-reduction reactions
- paired reactions in which electrons are transferred from one compound to another
- steal one and give one back
- oxidation reactions is always paired with reduction reaction (redox cycle)
reduction
- the gain of one or more electrons by a molecule
- molecules is said to be reduced
- electron acceptor, oxidizing agent
oxidation
- when an atom, ion, or molecule loses one or more electrons in a reaction
- the molecule is said to be oxidized
- electron donor, reducing agent
oxidation-reduction and hydrogen
- many biologic oxidations are referred to as dehydrogenation reactions
- because hydrogen ions as well as electrons are removed because hydrogen only has one electron
biosynthesis of organic compounds
- requires energy
- energy must be obtained through photosynthesis or chemosynthesis
photosynthetic reactions
- trap radiant energy of light and convert it into chemical bond energy in the form of ATP and carbs
genetics
study of heredity
an organisms genotype
- or genome
- its complete collection of genes
- genes direct all functions of the cell
- a particular segment of the chromosome constitutes a gene
organisms phenotype
- its physical traits that is a manifestation of the organisms genotype
- hair, eye colour
mutations
- a change in a DNA molecule (genetic alteration) that is transmissible to offspring
mutant
- the organism containing the mutation
mutagen
- a physical or chemical agent that when cells are exposed to it, the mutation rate increases
- mutation rate in bacteria higher than in human
3 categories of mutations
1) beneficial
2) harmful/lethal
3) silent (no real effect, may not be on a gene or amino acid)
ways in which bacteria acquire new genetic info
- lysogenic conversion
- transduction
- transformation
- conjugation
plasmid
- an extrachromosomal DNA molecule
- an organism that acquires a plasmid acquires new genes
episome
a plasmas that can either exist by itself or integrate into the chromosome
lysogenic conversion
- temperate (lysogenic) phages inject their DNA into a bacteria cell
- phage DNA integrates into bacterial chromosome but does not cause lytic cycle, this is lysogency
- bacterial cell exhibits new properties directed by the viral genes, this is lysogenic conversion
- bacteria acquire new viral genes
prophage
a phage that all that remains of it is DNA
lysogenic cell
the bacterial cell containing the prophage
transduction
- to carry across
- involves bacteriophages
- bacterial genetic material is carried across from one cell to another by a bacterial virus
- bacteria acquire new bacterial genes
- only small amount of genetic material are transferred
transduction steps
1) phage injects DNA into bacterial cell
2) bacterial DNA is fragmented as phage replicates
3) fragment of bacterial DNA incorporated into phage head
4) new phages are released when bacterial cell is lysed
5) phage containing bacterial DNA infects new cell
6) genes from original host are incorporated into chromosomes of new host
transformation
- bacterial cell becomes genetically transformed following uptake of DNA fragments from its environment
- not widespread in nature
competent bacteria
- bacteria that has the ability to absorb naked DNA into the cell
competence
the ability to absorb naked DNA into the cell
transformation steps
1) naked DNA in area of a competent cell enter the cell
2) recombination
3) DNA fragments integrate into host cell chromosome
4) DNA that has not recombined is broken down by enzymes
conjugation
- involves sex pilus
- bacterial cell with sex pilus (donor) attaches by means of sex plus to another bacterial cell (recipient)
- some genetic material is transferred from donor cell to recipient cell through conjugative pore
- usually a plasmid is transferred
plasmid and resistance factor
- a plasmid contains multiple genes for antibiotic resistance is known as a resistance factor or R-factro
- a bacterial cell that receives an R-factor becomes a super bug
conjugation steps
1) relaxes creates a nick in one plasma strand and transfers strand through the pore
2) recipient receive single stranded copy of plasmid
3) donor and recipient resynthesizes the complementary strands
4) cells separate each containing a plasmid
genetic engineering (recombinant DNA technology)
- involves techniques to transfer eukaryotic genes (human) into easily cultures cells to manufacture important gene products (mostly proteins)
- plasmid are frequently use as vehicles for inserting genes into cells
- many industrial and medical benefits
genetic engineering examples
- synthesis of antibodies
- antibiotics
- drugs
- vaccines
- synthesis of important enzymes and hormones for treatment of disease
genetic engineering steps
1) target DNA and vector DNA combine
2) rDNA introduced into host cell
3) isolate cells containing cloned genes
4) produce protein from cloned gene
gene therapy
- involves insertion of a normal gene into cells to correct a specific genetic disorder caused by a defective gene
- viral delivery is most common method for inserting genes into cells
- specific viruses are selected to target DNA of specific cells
- genes may someday be regularly prescribed as drugs in the treatment of diseases like autoimmune, sickle cell anemia, cancer, cystic fibrosis, heart disease
