Chapter 11 - Microbial Nutrition Flashcards Preview

Microbiology > Chapter 11 - Microbial Nutrition > Flashcards

Flashcards in Chapter 11 - Microbial Nutrition Deck (34)
Loading flashcards...
1
Q

What three things do Microbes need?

A

Carbon, Energy and Electrons

2
Q

All Organisms are what based?

A

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

3
Q

Heterotrophs

A

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

4
Q

Autotrophs

A

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

5
Q

Two sources of Energy

A

Light or Chemical Energy

6
Q

Light Energy

A

comes from the sun :P

7
Q

Chemical Energy

A

Comes from organic or inorganic chemicals

8
Q

Phototrophs

A

Use Light Energy (light eaters)

9
Q

Chemotrophs

A

Use Chemical energy (Chemical eaters)

10
Q

Chemical Energy can come from where?

A

Inorganic or Organic sources

11
Q

Inorganic Chemical Energy Source?

A

Lithotroph (Rock eater)

12
Q

Organic Chemical Energy Source?

A

Organotroph (organic eater)

13
Q

Macronutrients

A

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

14
Q

What is Nitrogen needed for?

A

Formation of proteins, nucleic acids and other cell components

15
Q

What is Phosphorus needed for?

A

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

16
Q

What is Sulfur needed for?

A

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

17
Q

What is Potassium needed for?

A

enzymes

18
Q

What is Magnesium needed for?

A

Stabilize Ribosomes and membrane

19
Q

Growth Factors

A

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

20
Q

Passive Diffusion

A

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.

21
Q

Facilitated Diffusion

A

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

22
Q

Carrier proteins - Facilitated Diffusion

A

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

23
Q

Active Transport

A

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

24
Q

Primary Active Transport

A

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

25
Q

ABC system

A

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.

26
Q

Secondary Active Transport

A

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

27
Q

Proton Motive Force

A

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.

28
Q

Uniport

A

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

29
Q

Symporters

A

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

30
Q

Antiporters

A

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

31
Q

Group Translocation

A

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.

32
Q

phosphoenolpyruvate: sugar phosophotransferase system (PTS)

A

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.

33
Q

Iron

A

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

34
Q

Siderophores

A

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.