1. Microbial metabolism Flashcards
Define metabolism
All chemical and physical workings of the cell
Define anabolism
assembles smaller molecules into larger macromolecules needed for the cell
Define catabolism
Degrades macromolecules into smaller molecules and yields energy
What are the two processes of metabolism?
anabolism and catabolism
What are the six basic elements needed for life?
carbon, nitrogen, oxygen, hydrogen, phosphorus, and sulfur
What are the six macromolecules that make up the cell?
protein, lipid, DNA, RNA, polysaccharide, lipopolysaccharide
What are the ways that cells transport nutrients into the cell?
passive and active transport
Define passive transport
molecules moving from a higher to lower concentration with the concentration gradient
What are the three types of passive transport?
diffusion, facilitated diffusion, and osmosis
What is facilitated diffusion?
diffusion using a transporter
What are the two types of facilitated diffusion?
nonspecific and specific
Is passive transport regulated?
yes
What is active transport?
Transportation against the concentration gradient
What is the main difference between active and passive transport?
active uses energy
What type of energy does active transport use?
PMF or ATP
What are the three types of active transport transporters?
simple transport, group translocation and ABC system transport
Define simple transport
transport driven by proton motive force
What are the two types of simple transport?
using a symport or antiport
What is a symport?
solute and H+ are co transported in one direction
What is an antiport?
solute and H+ are transported in opposite directions
Define group translocation
the transported substance is chemically modified
What drives group translocation?
energy rich organic compounds
What is an ABC transporter?
ATP is used to bind periplasmic proteins to transported substance
How many different systems have been found in prokaryotes using ABC transport?
200+
What two proteins are required in ABC transport?
transmembrane and ATP hydrolyzing proteins
What are the four critical components a cell uses once resources are inside it?
electron or hydrogen carriers, energy rich compounds, enzymes, and substrates
How do electron carriers work in the cell?
NAD+ and NADH perform redox reactions without being consumed
What is the intermediary electron carriers use?
coenzymes
What do electron carriers allow in the cell to happen?
many different donors and acceptors to interact
What happens when energy rich compounds’ bonds break?
release energy
What is the structure of enzymes?
protein and non-protein
What is the function of enzymes?
increase reaction rate by lowering the activation energy
What is the role enzymes play in the cell?
oxidation
Define oxidation
movement of electrons
What makes up the metabolic pathways of the cell?
enzyme activity
What are the two ways enzymes are regulated by the cell?
change in the enzyme number or change in the enzyme itself
How are the number of enzymes expressed regulated?
repressed or induced
Define competitive inhibition
a normal and a similar substrate compete for the active site on the enzyme
What happens if the competitive inhibitor binds to the enzyme?
reaction is blocked because the competitive inhibitor isn’t able to become a product
Define noncompetitive inhibition
a regulatory molecule binds to the regulatory site on an enzyme changing the shape of the active site and preventing the regulatory molecule from binding
What are the two ways enzymes can be changed?
competitive and noncompetitive inhibition
What are the common catabolic pathways?
glycolysis, Kreb’s cycle and electron transport chain
What catabolic pathways is substrate level phosphorylation?
glycolysis
Define substrate level phosphorylation
energy rich phosphate bond from organic compound is transferred to ADP making ATP
What happens in glycoslysis?
incomplete oxidation of glucose
What pathways use glycolysis?
fermentation and respiration
What is the formula for glycolysis?
glucose + 2 ATP + 2 NAD+ = 2 pyruvate + 4 ATP + 2 NADH
When does the Kreb’s cycle occur?
when fermentation doesn’t
What happens in the Kreb’s cycle?
glucose is fully oxidized and broken down into single carbon molecules
What is an example of substrate level phosphorylation in the Kreb’s cycle?
2 ATP being produced
What is the importance of the electron carriers in the Kreb’s cycle?
generating ATP
What is the formula for the Kreb’s cycle?
2 Acetyle CoA + 6 NAD+ + 2 FADH+ = 2 ATP + 6NADH + 2FADH2 + 4 Co2
What part of the cell does the electron transport chain occur in?
membrane
What is oxidative phosphorylation?
transfer of electrons to generate ATP
What catabolitic pathway uses oxidative phosphorylation?
ETC
How can the ETC become aerobic?
if the terminal electron acceptor is oxygen
How can the ETC become anaerobic?
if sulfate, nitrate, carbon dioxide, ferric iron, or carbonate is the final electron acceptor
What is the formula for the electron transport chain?
10 NADH + 2 FADH2 + O2 = 34 ATP + H2O + 10NAD+ 2 FADH+
Define photophosphorylation
light mediated ATP synthesis
Define fermentaiton
anaerobic catabolism in which organic compounds donate and accept electrons
Define respiration
aerobic or anaerobic catabolism in which a donor is oxidized with O2 as an electron acceptor
What is the purpose of fermentation?
recycles electron carrier so glycolysis can keep going
What products of fermentation have purpose to the cell?
NAD+
What is the formula for fermentation?
2 Pyruvate + 2 NADH = 2NAD+ + (2 organic acid) or (2 alcohol + Co2)
How does the Kreb’s cycle vary between aerobic and anaerobic respiration?
change in electron carriers produced
Do facultative organisms do respiration or fermentation?
both
Why do facultative organisms switch between respiration and fermentation?
energetic benefit and electron acceptor availability
How many ATP are generated during aerobic respiration?
38
How many ATP are produce during fermentation?
2
How fast can fermentative bacteria grow?
equally as fast as respirating bacteria
Define chemolithotroph
uses inorganic chemicals as electron donors
Describe the process of chemolithorophy
oxidation of inorganic electron source, ETC generates PMF, ATP is generataed
Is chemolithotroph aerobic or anaerobic?
aerobic
What is oxygenic photophosphorylation?
water and light energy go in and oxygen comes out
What type of organism does oxygenic photophosphorylation occur in?
plants, algae, cyanobacteria
What are the types of light pigments in oxygenic photophosphorylation?
chlorophyll, carotenoids, and phycobilins
How is anoxygenic photophosphorylation different than oxygenic photophosphorylation?
no oxygen is produced
What bacteria use anoxygenic photophosphorylation?
green and purple
What is chlorophyll replaced with in anoxygenic photophosphorylation?
bacteriochlorophyll
What is the proton motive force?
provides direct power
What two things use PMF?
flagella and simple active transport
What does the proton motive force do?
use ATP to push hydrogens outside of the membrane
Where does the ETC take place in prokaryotes?
plasma membrane
Where does the ETC and Kreb’s cycle take place in eukaryotes?
inner mitochondrial membrane
Where does glycolysis take place in eukaryotes?
outside the mitochondria
Where does photosynthesis take place in plant algae?
chloroplast
Where does photosynthesis take place in cyanobacteria?
cytoplasmic membrane
What are the two ways monosaccharides, amino acids, fatty acids, nitrogen bases, and vitamins come into the cell?
from the outside in the form of nutrients
sythesized through cellular pathways
How is carbohydrate biosynthesis used?
alternative pathways
How are amino acids, proteins, and nucleic acids sythesized?
some can make them on their own but others aquire them from their diets
What is a chemoorganotroph?
conserve energy from organic chemicals
What is a chemolithotroph?
oxidize inorganic compounds
What is a phototroph?
convert light energy into ATP
What are heterotrophs?
obtain carbon from organic sources
What are autotrophs?
obtain carbon from Co2
Define amphibolism
the property of a system to integrate catabolic and anabolic pathways to improve cell efficiency
What two cycles use amphibolism?
glycolysis and Kreb’s cycle
What is ethanol fermentation important for?
alcohol and bread
What color pigment are carotenoids?
yellow, orange, red
What color pigment is chlorophyll?
green
What color pigment is phycobilins?
red, blue-green
What are the four major classes of electron carriers used?
cytochromes, flavoproteins, iron-sulfur proteins, and quinones
What is an organic compounds?
made from carbon
Why is lactic fermentation good for?
making of yogurt and cheese
What is a lithotroph
uses inorganic molecules for energy
What is the purpose of mixed acid fermentaiotn?
used to make vaccines and vitamins
What is nitrogen fixation?
conversion of organic nitrogen into nitrogen gas
Anabolic pathways use energy created from what?
catabolic pathways
What are the two strategies of carbon sources?
autotroph and heterotroph
What are the three stragesies of energy source?
organotroph, phototroph, lithotroph
What is an organotroph/chemotroph?
use organic molecules as their electron donor
WHat are the two strageties for electron acceptors?
aerobic and anerobic
How does an aerobic organism get its electron acceptor?
through oxygen
How does an anaerobic organism get its electron acceptor?
something other than oxygen
