exam 2 study guide

What are the essential macronutrients?

C,O,H,N,P,S and Mg2+, Ca2+, Fe2+, K+

what are the essential micronutrients?

Co, Cu, Mn, Zn, Mo, Ni

heterotrophs

use performed organic molecules for carbon

autotrophs

fix CO2 and assemble into organic molecules (mainly sugars)

phototrophy

use light energy

lithotrophy

energy from the oxidation of minerals

What is the purpose of the Nitrogen cycle?

converts nitrogen into essential life components like proteins and DNA

homolactic fermentation (cheese)

two lactic acids

ethanolic fermantation

two ethanol two CO2

heterolactic fermentation (swiss cheese)

1 lactic acid, 1 ethanol, 1 CO2. Pr-yellow MR- yellow

mixed acid fermentation (industrial reactions)

acetate, formate, lactate, succinate, ethanol, H2, CO2. PR-yellow MR-red

MR

turns red if organism uses the mixed acid pathway/ ph less 4.4

passive transport

simple and facilitated diffusion

active transport

coupled transport-moving a driving ion down its gradient is used to move a solute up its gradient., ABC transport- binds to surface protein→opens channel → movement into cell

bacterial division

binary fission, where one parent cell splits into two equal daughter cells.

EXCEPTION: some divide asymmetrically.Others split into more than two cells. Hyphomicrobium divides by budding

batch culture

A liquid medium within a closed system

chemostat

ensures logarithmic growth by constantly adding and removing equal amounts of culture media. think human GI tract

Continuous culture

all cells in a population achieve a steady state, which allows detailed study of bacterial physiology.

Direct microscopic count

counted on a special microscope slide, called a counting chamber.

Viable cell count

count replicating and colony forming cells

Generation time and expo growth formulas

Nt= No x 2^n.

n= log base 2 (Nt/No)

N= G/t

cell count formula

CFU/mL= # of colonies/ volume plated x dilution factor

complex media

nutrient rich but poorly defined

synthetic media

precisely defined

enriched media

complex media to which specific blood components are added.

selective media

favor the growth of one organism over another

Differential media

exploit differences between two species that grow equally well.

catabolism

breakdown complex molecules into simpler ones. provides energy for anabolism

anabolism

reactions that build cells

NADH

carries three times as much energy as ATP.

FADH2

is another coenzyme that can transfer electrons. is reduced by two electrons and two protons

ATP

contains a base, sugar, and three phosphates. attached by two high energy bond and upon hydrolysis,

they release energy

ATP transfer energy in three different ways

Hydrolysis-releasing phosphate (pi)- biosynthesis

Hydrolysis-releasing pyrophosphate (PPi)- transcription

Phosphorylation of an organic molecule- glycolysis

key differences b/t subtrate level phos and oxidative phos

Substrate-level phosphorylation directly transfers a phosphate group from a reactive intermediate molecule to ADP, while oxidative phosphorylation uses energy from an electron transport chain and a proton gradient to synthesize ATP

oxidative phos

A complex, multi-step process where electrons move down an electron transport chain. This movement pumps hydrogen ions (protons) across a membrane to create a concentration gradient. Protons then flow back through an enzyme called ATP synthase, which drives the bonding of free phosphate to ADP.

substrate level phos

An enzyme directly moves a phosphate group from a high-energy metabolic intermediate (a substrate) onto ADP. It is a simple, single-step reaction. [1, 2, 3]

EMP pathway (glycolysis) key intermediate and products

key intermediate: G3P

Products: 2 ATP, 2 Pyruvate, 2NADH

ED pathway key intermediate and products

key intermediate: 6-P- gluconate

Products: 1 ATP, 1 NADH, 1 NADPH, 2 Pyruvates

PPP pathway key intermediate and products

key intermediate: Ribulose 5-P

Products: 1 ATP, 2 NADPH, 3-7 Carbon sugar phosphates

EMP pathway description

2 stages- energy investment and energy yield. Stage 1: glucose activated by 2 phosphorylations-uses 2 ATP up. Fructose-1,6-bisphosphate is split into → DHAP and G3P. Stage 2: each G3P converted to pyruvate (2 total per glucose), 2 NADH produced by reduction of NAD+, 2 NET ATP PRODUCED.

purpose of glycolysis

to break down a single molecule of glucose into two molecules of pyruvate, releasing usable cellular energy in the process

location of glycolysis

in cytosol of cytoplasm

Location of TCA

in cytosol of cytoplasm

location of ETS

plasma membrane

purpose of ETS

to generate a proton motive force across the cell membrane, which drives the synthesis of ATP and powers essential cellular work. GENERATES MOST ATP!!!!

purpose of TCA

to generate metabolic energy and provide essential carbon building blocks for cell growth. oxidizes Acetyl. COA into CO2. Uses NADH and FADH2

overall products from glycolysis of glucose molecule/

two pyruvate molecules, two net ATP molecules, two NADH molecules, two hydrogen ions (H⁺), and two water molecules (H₂O)

Steps to know of glycolysis!! 5

1. hexokinase→ ATP phosphorylates glucose to plucose 6-phosphate.

3. a-fructose 6-phosphate→ ATP phosphorylates fructose 6-phosephate to fructose 1,6- bisphosphate

6. G3P→ G3P loses 2 e and is phosphorlyated to 1,3- bisphosphoglycerate.

7. 1,3 Biphosphoglycerate→ Phosphoryl group is lost to ATP forming 3- phosphoglycerate

10. Phosphoenolpyruvate→ phosphoryl group is lost to ATP forming pyruvate

pyruvate in respiration

linkage step to start TCA

pyruvate in fermentation

reduced to lactate (in animals) or alcohol and carbon dioxide (in other organisms)- NET GAIN OF 2 ATP

Conversion of Pyruvate to Acetyl CoA

PDC converts a three-carbon molecule called pyruvate into a two-carbon molecule called acetyl-CoA inside the mitochondrial matrix through a process called oxidative decarboxylation.

Products of TCA

2 CO2, 3 NADH, 1 FADH2, 1 ATP

process of TCA cycle

(TCA or Krebs cycle) is an 8-step closed-loop chemical pathway in the mitochondrial matrix that oxidizes acetyl-CoA into carbon dioxide to capture energy in reduced coenzymes.

What is the importance of the intermediates in the TCA cycle?

They are used for biosynthesis.

overall products of each TCA cycle.

(3 NADH, 1 FADH2, 1 ATP, 2 CO2 ) → per turn

(6 NADH, 2 FADH2, 2 ATP, 6 CO2) → per glucose

how does each Acetyl-CoA goes through the TCA cycle and produces CO2, ATP or GTP, NADH and FADH2.

Each molecule of Acetyl-CoA goes through one turn of the tricarboxylic acid (TCA/Krebs) cycle to release two molecules of CO2, make one ATP or GTP, and load up electron carriers with three NADH and one FADH2

why would a cell would want to use the glyoxylate bypass pathway

A cell uses the glyoxylate bypass pathway to convertsimple two-carbon molecules, like acetate or fatty acids, into net carbohydrates (glucose) without losing carbon atoms as carbon dioxide

advantages and disadvantages behind the glyoxylate bypass.

advatanges: saves carbon and regenerates glucose

disadvantages: makes less NADH and less energy (ATP)

substrate level phosphorylation

when an enzyme directly transfers a high-energy phosphate group from a metabolic intermediate molecule (the substrate) onto adenosine diphosphate (ADP)

Electron transport on E coli

transfers electrons from donors to acceptors while pumping protons into the periplasmic space to generate energy

List the functional components (protein complexes) NADH donates electrons to the E. coli ETS.

NADH Dehydrogenase I, NADH Dehydrogenase II

what is the purpose of the proton motive force (PMF) and the role of ATP synthase in making

ATP.

The proton motive force (PMF) acts as an electrochemical battery across a cell membrane that stores energy to drive ATP synthesis, active transport, and cellular motion. ATP synthase is a multi-subunit protein enzyme that sits embedded in the membrane.

Where (in which part of the cellular compartment) are the proton motive force (PMF) created in

E. coli and mitochondrion.

E coli: Plasma membrane

Mitochondrion: Inner mitochondria

Substrate-Level Phosphorylation

An enzyme binds to both the phosphorylated substrate and ADP. The enzyme snips the high-energy phosphate bond from the substrate and glues that phosphate right onto ADP, turning it into ATP.

Oxidative Phosphorylation

Indirect synthesis via a proton gradient and ATP synthase. HIGH ATP YEILD. O2 NEEDED

basic overview of anaerobic respiration

• A full cellular respiration pathway that does use an electron transport chain.

• The difference: Instead of using oxygen (O2) as the final trash can for electrons at the end of the chain, it uses an inorganic molecule like sulfate (SO4 2-), nitrate (NO3-), or carbon dioxide (CO2).

• Who does it: Many prokaryotes (bacteria and archaea).

• The payoff: It makes more ATP than fermentation alone because it runs an electron transport chain, though still less than aerobic respiration with oxygen. [1, 2, 3, 4, 5]

What is the energy yield when comparing aerobic and anaerobic respiration.

aerobic (w O2)- 38 ATP

anaerobic (w/o O2)- 2 ATP

terminal electron acceptors in aerobic vs anaerobic respiration.

aerobic respiration- O2

Anaerobic respiration- nitrate, sulfate, CO2, Fe3+