Chapter 11 - Microbial Nutrition

Question 1

What three things do Microbes need?

Answer 1

Carbon, Energy and Electrons

Question 2

All Organisms are what based?

Answer 2

Carbon - proteins, carbohydrates, lipids, nucleic acids - fundamental cores of Carbon

Question 3

Heterotrophs

Answer 3

Other eaters - Use reduces, performed organic substances as the carbon source

Question 4

Autotrophs

Answer 4

Self Feeders - rely on CO2 as carbon source, reducing or fixing it

Question 5

Two sources of Energy

Answer 5

Light or Chemical Energy

Question 6

Light Energy

Answer 6

comes from the sun :P

Question 7

Chemical Energy

Answer 7

Comes from organic or inorganic chemicals

Question 8

Phototrophs

Answer 8

Use Light Energy (light eaters)

Question 9

Chemotrophs

Answer 9

Use Chemical energy (Chemical eaters)

Question 10

Chemical Energy can come from where?

Answer 10

Inorganic or Organic sources

Question 11

Inorganic Chemical Energy Source?

Answer 11

Lithotroph (Rock eater)

Question 12

Organic Chemical Energy Source?

Answer 12

Organotroph (organic eater)

Question 13

Macronutrients

Answer 13

Other elements needed by cells - such a Nitrogen, phosphorus, Sulfur, potassium, and Magnesium (C, H and O also considered macros)

Question 14

What is Nitrogen needed for?

Answer 14

Formation of proteins, nucleic acids and other cell components

Question 15

What is Phosphorus needed for?

Answer 15

crucial component of nucleic acid (sugar-phosphate backbone) phospholipids, ATP

Question 16

What is Sulfur needed for?

Answer 16

necessary for a few amino acids, as well as several Vitamins

Question 17

What is Potassium needed for?

Answer 17

enzymes

Question 18

What is Magnesium needed for?

Answer 18

Stabilize Ribosomes and membrane

Question 19

Growth Factors

Answer 19

Organic molecules that fall into 3 categories - 1. Amino acids 2. Purines and pyrimidines 3. Vitamins

Question 20

Passive Diffusion

Answer 20

aka simple diffusion - passage across the cell membrane of simple molecules and gasses (CO2, O2, H2O). Must use a concentration gradient with higher concentration on outside than inside. As more transported, gradient goes down and slows rate of diffusion.

Question 21

Facilitated Diffusion

Answer 21

Uses concentration gradient with higher on outside of cell, but differs w/ use of carrier proteins (permeases). Part of Passive Transport.

Question 22

Carrier proteins - Facilitated Diffusion

Answer 22

Embedded w/in a cell membrane and provide a channel across the membrane barrier to allow for passage of larger molecules. Each typically exhibits specificity. As Gradient dissipates, passage of molecules stops

Question 23

Active Transport

Answer 23

use of metabolic energy to transport substance through carrier proteins against a concentration gradient - all types of active transport utilize carrier proteins

Question 24

Primary Active Transport

Answer 24

Involves the use of chemical energy, such as ATP. An example is the ABC system.

Question 25

ABC system

Answer 25

Utilizes ATP-Binding Cassette transporters. Composed of 3 parts 1. Membrane spanning proteins that form across cell membrane, 2. ATP binding region that hydrolyzes ATP 3. substrate-binding protein that binds and ferries appropriate substance to the membrane spanning proteins.

Question 26

Secondary Active Transport

Answer 26

Utilizes energy other than ATP, such as proton motive force.

Question 27

Proton Motive Force

Answer 27

An Ion gradient that develops when cell transports electrons during energy conserving processes. Positively charged protons accumulate along outside of negatively charged cell, creating a proton gradient between inside and outside.

Question 28

Uniport

Answer 28

Type of Simple transport. Transfer single substance across the membrane - either in or out

Question 29

Symporters

Answer 29

Transport two substances across the membranes at the same time, typically proton paired with another molecule.

Question 30

Antiporters

Answer 30

Transport two substances across the membrane, but in opposite directions. As one enters, the other transports out.

Question 31

Group Translocation

Answer 31

Distinct type of active transport - uses energy from energy rich organic compounds that are not ATP. Also differs from simple and ABC in that the substance being transported is modified.

Question 32

phosphoenolpyruvate: sugar phosophotransferase system (PTS)

Answer 32

best studied example of group translocation. Uses molecule PEP to transport sugar into cell. Phosphate is transferred from the PEP to incoming sugar during process.

Question 33

Iron

Answer 33

Required by microbes for function of their cytochromes and enzymes. Growth-limiting micronutrient

Question 34

Siderophores

Answer 34

Organic Molecules that chelate or bind ferric iron with high affinity. Released by the organism into surrounding environment, where they bind to any available ferric iron. The complex is then bound by a specific receptor on outside of cell, transporting iron into cell.