Chapter 8
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Define catabolic pathway
Breaks down the substances and releases energy
Define anabolic pathway
Combine energy and molecules to build new substances
Define amphibolic pathway
Dual role, can be used for both breaking down and building substances
Define ATP
Adenosine triphosphate. Made by catabolic reactions and provides the
energy for anabolic reactions
Define ADP
Adenosine diphosphate. Contains two phosphate groups
Define AMP
Adenosine monophosphate. Formed when cells dephosphorylate ADP
(remove last phosphate group of ADP)
Define catalyst
Only needed in small amounts to make a reaction happen faster. Not
permanently changed
Define reaction rate
Speed at which a reaction occurs
Define active site
Site of an enzyme that interacts with the substrate to generate a
chemical reaction
Define activation energy
Minimum amount of energy required to start a chemical reaction
Define reactant
Held by cells in their proper orientation and lower the energy
required for starting, using enzymes
Define product
End result
Define coenzyme
Cofactors that can move about to other factors anchored to the enzyme
they help, can be vitamins, can collect electrons from one reaction
and shuttle them to other reactions. In metabolism include NAD+,
NADP+, FMN, and FAD
Define cofactor
Needed by enzymes to function
Define ribozymes
Enzymes that are made of nucleic acid RNA
Define denatured
Enzymes and other proteins. Exposure to high temperatures, lose 3D
structure, and become nonfunction. Can be reversible and irreversible
Define allosteric activation
When a regulatory molecule increases enzyme activity by binding to
the enzyme's allosteric site
Describe how enzymes function in anabolic and catabolic reactions
Hold reactants in their proper orientation and lower the energy
required for starting the reaction.
What factors affect enzyme activity
Drugs, environmental factors.
Temperature, pH, cofactors, temperature, how much substrate,
phosphorylation state, presence of inhibitors
Define feedback inhibition
(Both competitive and non-competitive inhibitors)
Competitive inhibitors, slow reactions by competing with a substrate
for the target enzyme's active site. Enzyme cannot carry out reaction
until competitive inhibitor leaves the active site, allowing substrate
to enter. Can be reversible.
Noncompetitive inhibitors, don't compete with substrate, decrease
enzyme activity by binding to the enzyme at a site other than the
active site. Deform enzyme structure so substrate cannot interact with
the active site. Can permanently inhibit an enzyme.
Feedback inhibition, enzyme form that slows down (or turn off)
biochemical pathways to help cells be efficient. Is reversible, cells
make a product to a point of sufficient quantities exist, then the
pathway is blocked from making any more. When product decreases to
less than what the cell needs, block goes away allowing the cell to
make more again. Ex amino acids and nucleotides.
Catabolism process of cell respiration: aerobic/anaerobic, fermentation
Cellular respiration, collection of reactions that extract energy
from foods using redox reactions and then transfer that energy into
bonds of ATP.
Aerobic or anaerobic, 6 glucose, glycolysis, intermediate step,
krebs cycle, electron transport chain. ATP
Fermentation, 6 glucose, glycolysis, fermentation, ATP plus end
products (alcohols, acids)
Diagram of an ATP molecule
Three phosphates, ribose, adenine
Summary of glycolysis
Extracts energy from complex carbohydrates (starches), disaccharides
(sucrose, lactose), simple sugars (mannose, fructose, glucose)
Ten reactions in two stages: energy investment state, payoff stage.
In the cytoplasm of prokaryotes and eukaryotes, does not require
energy. No carbons are removed
6 carbon sugar invest 2 ATP, 6 carbon glucose is split to make 2
pyruvic acids. NAD+ is reduced to NADH. Produces 4 molecules of ATP
Summary of intermediate step
Converts both molecules into acetyl-CoA (2 carbon molecule) and
releases carbon dioxide.
Summary of Krebs cycle
Formation of citric acid from oxaloacetic acid and acetyl-CoA.
Produces ATP and lots of reduced factors (NADH, FADH2). Runs once for
every acetyl-CoA made in intermediate step, therefor runs twice for
each glucose molecule entered. Every carbon is turned into carbon dioxide.
How/where do these processes occur in both prokaryotes and eukaryotes?
What is ATP synthase?
Glycolysis, cytoplasm of prokaryotes and eukaryotes
Intermediate step, in cytoplasm of prokaryotes and eukaryotes
Krebs cycle, cytoplasm of prokaryotes and matrix of mitochondria of eukaryotes
ATP synthase, enzyme in electron transport chain that captures
energy of protons, and uses it to recharge ADP to ATP. Found in
mitochondrial inner membrane of eukaryotes and plasma membrane of prokaryotes.
What are some various end products from anaerobic fermentation?
Why are we concerned about these products?
Homolactic fermentation, pyruvic acid made in glycolysis is only
reduced to lactic acid. Two ATP molecules that are gained are made in
glycolysis. Use this when oxygen is limited as during anaerobic exercise
How are lipids and proteins catabolized to produce ATP?
Lipids, lipase breaks lipids into glycerol and fatty acids. Glycerol
component is converted to DHAP and enter glycolysis. Fatty acids are
broken down, two carbons at a time, to acetyl-CoA molecules that can
enter krebs cycle via beta oxidation
Proteins, proteases and peptidases break proteins down into
peptides and then amino acids. Amino acids are recycled to make more
proteins. Must be stripped of amine group NH2 by deamination.
catabolized through krebs cycle.
How do bacteria use biosynthesis to make macromolecules?
Anabolic reactions that require ATP
What energy sources microbes use to make ATP?
Phototrophs, use energy from light to make ATP
Chemotrophs, energy found in chemical bonds of their nutrients to
make ATP
Mixotrophs, use variety of sources, and diverse in how they obtain energy.
How metabolic pathways and their products are used to identify bacteria.
Examples of metabolic tests to identify bacteria
Biochemical tests, amino acid catabolism tests, fermentation tests,
oxidase and catalase tests,
Chap 9
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Define pathogen
Include viruses, prions, bacteria, protozoans, helminths, and fungi.
Cause infectious diseases
Define opportunistic pathogen
Only cause disease when their host is weakened in some way
Define endemic
Infections detected in a population or region
Define pandemic
When a epidemic spreads to numerous countries
Define emerging pathogen
Newly identified agents (pathogens) that caused only sporadic cases,
but increasingly became more common
Define reemerging pathogen
Was under control due to prevention but is now resurfacing.
Define zoonotic disease
Spread from animals to humans
Define noncommunicable
Do not spread from person to person
Define contagious
Communicable diseases easily transmitted from one host to the next
Define signs
Indicators of disease that can be measured or verified, fever, rash.
Define symptoms
Sensed by patients and subjective rather than precisely measurable,
pain, fatigue, and nausea
Define latent diseases
Infected has no symptoms of the disease and is not contagious
Define chronic diseases
Slower onset and progression
Define acute diseases
Rapid onset and progression of a disease
Define noninfectious disease
Illnesses not directly caused by pathogens
Define susceptible host
Host that can develop the disease
Define obligate intracellular pathogen
Viruses and certain bacteria and protozoans, only replicate inside a
host cell and are impossible to grow as independent pure cultures.
Define reservoir
Animate or inanimate habitat where the pathogen is naturally found
Define source
Disseminates the agent from the reservoir to new hosts
Define endogenous source
Pathogen comes from the hosts own body
Define exogenous source
Source of an infecting pathogen that is external to the host
Define vector
Organisms (arthropods, rodents) that spread infectious agents to
other susceptible hosts
Define morbidity
Existence of diseases
Define prevalence rate
Measure of frequency that describes morbidity in a given population.
To calculate, take total number of disease cases during given time and
divide it by the total number of people in the defined population
during that same time
Define incidence rate
Number of new cases in a defined population during a defined time fram
Define duration
How long the infection lasts
Define epidemiology
Medicine that aims to understand and prevent illness in communities
Define HAI
Healthcare acquired infection, nosocomial infection. Infection that a
patient develops while receiving care in a healthcare setting
Define localized infection
Infection that is restricted to a specific part of the body
Define systemic infection
Infection widespread throughout the body
Define virulence factor
Pathogens use to stick/adhere
What are Koch's postulates
Four criteria used to evaluate what pathogen is the agent of a
particular disease
1. The same organism must be present in every case of the disease
2. Organism must be isolated from the diseased host and grown as a
pure culture
3. The isolated organism should cause the disease in question when
it is introduced (inoculated) into a susceptible host
4. The organism must then be re-isolated from the inoculated,
diseased animal
Table 9.2
Five stages of infectious disease
1. Incubation period
2. Prodromal phase
3. Acute phase
4. Period of decline
5. Convalescent phase
Figure 9.1 mechanisms of direct and indirect transmission
Direct: person to person, animal, environment, vertical
Indirect: Airborne, vehicle, vector (biological), vector (mechanical)
Describe 5 stages of infectious disease
1. Incubation period, time between infection and development of symptoms.
2. Prodromal phase, early symptoms develop
3. Acute phase, peak of the disease
4. Period of decline, replication of the infectious agent is
brought under control, symptoms start to resolve
5. Convalescent phase, patient recovers, some cases the pathogen is
kept latent in the patient
Epidemiological triangle, what can be done to stop the spread of infection
When host, agent, and environment overlap, there is possibility of
disease. Environmental factors, host factors, etiological agent
Taking away a link of the triangle can stop disease spread. Public
education, quarantine, vector control,
Explain the purview of the WHO and the CDC?
What is the MMWR?
CDC, Centers for disease control and prevention. WHO, world health organization
What is an HAI (nosocomial) Why are they a problem?
Examples of most common type of how to prevent them
Diseases that develop from a healthcare intervention. Direct and
indirect contact, contaminated medical devices and healthcare workers
hands are most common sources. Can be localized and systemic
Table 9.5 fig 9.10 describe actions that prevent/reduce HAI's
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What is the NNDSS? Public health surveillance?
NNDSS, National notifiable diseases surveillance system
Five examples of vaccine preventable diseases
Smallpox, polio, guinea worm