Life of bacteria

Question 1

Nutrition types of m.o.

Answer 1

two ways how to they obtain carbon and capture energy

Question 2

autotrophy

Answer 2

self-feeding

Question 3

heterotrophy

Answer 3

other-feeding

Question 4

autotrophs use

Answer 4

carbon dioxide as a carbon source → synthesize organic molecules

Question 5

photoautotrophs

Answer 5

energy from light by photosynthesis

- cyanobacteria

Question 6

chemoautotrophs

Answer 6

• energy from oxidizing simple inorganic substances such as sulfides and nitrites
• nitrifying bacteria

Question 7

heterotrophs

Answer 7

• get carbon from ready-made organic molecules

- obtain from other organisms (dead or living)

Question 8

chemoheterotrophs

Answer 8

chemical energy from breaking down ready-made organic compounds
(metatrophs + paratrophs)

Question 9

metatrophs

Answer 9

obtain carbon from glycogen, starch and cellulose

Question 10

paratrophs (parasites)

Answer 10

obtain carbon from soluble carbohydrates and nitrogen from AAs

Question 11

photoheterotrophs

Answer 11

chemical energy from light to require organic substances as alcohols, fatty acids or carbohydrates as carbon sources

Question 12

aerobes

Answer 12

• require molecular oxygen for metabolism + growth
• use oxygen for oxidation of nutrients and production of energy
• final acceptor of electrons in ETC

Question 13

anaerobes

Answer 13

• dont require oxygen
• oxygen = toxic
• oxygen containing inorganic molecules (nitrates, nitrites) = final acceptors of electrons in ETC

Question 14

facultative anaerobes

Answer 14

• grow either in presence or absence of oxygen

- can generate ATP in aerobic and anaerobic conditions

Question 15

microaerophiles

Answer 15

• require oxygen in very low levels (2-10%)

- capnophiles → need elevated amount of carbon dioxide

Question 16

bacterial enzymes are classified into

and subdivided into

Answer 16

→ endoenzymes intracellularly
→ exoenzymes secreted to environment
- subdivided into six groups acc. to catalyzed reactions

Question 17

oxidoreductase

Answer 17

• oxidation reduction reaction

- oxygen and hydrogen are added or released

Question 18

transferase

Answer 18

• transfer specific functional groups (amine) from one molecule to another (alanine transaminase)

Question 19

hydrolase

Answer 19

• participate in hydrolysis reactions (addition of water)

Question 20

lyase

Answer 20

• transfer groups of atoms without hydrolysis reaction

Question 21

isomerase

Answer 21

• reorganize atoms inside the molecule e.g. glucose phosphate isomerase

Question 22

ligase

Answer 22

join two large molecules by using ATP energy

Question 23

uptake of nutrients by the bacterial cell

Answer 23

• passive diffusion

- active transport

Question 24

passive diffusion

Answer 24

• concentration gradient of substances
• transmembrane proteins (porins) form pores in membrane and cell wall
• assist in transport function
• pores + channels allow entry of ions and small hydrophilic molecules by passive diffusion

Question 25

active transport

Answer 25

- against concentration gradient - permeases involved in a.t. - p. form phosphotransferase system → uses energy from high energy phosphoenolpyruvate molecules - PEP in cytoplasm → energy + phosphate group to a permease in membrane → transfers phosphate to sugar molecule and moves sugar across membrane - phosphorylated sugar is trasnported inside cell and prepared for metabolism

Question 26

metabolism

Answer 26

- sum of all chemical processes which occur in the bacterial cell - consists of catabolism and anabolism

Question 27

catabolism

Answer 27

chemical reactions that release energy by breaking complex molecules into simpler ones

Question 28

anabolism

Answer 28

chemical reactions which require energy to synthesize complex molecules from simpler ones

Question 29

catabolic reactions

Answer 29

- provide energy for bacteria that is required for bacterial life processes → movement, active transport of nutrients and synthesis of complex molecules - involve electron transfer → energy to be captured in high-energy bonds in ATP and similar molecules - ET = oxidation and reduction

Question 30

anabolic reactions

Answer 30

- bacterial growth, reproduction and repair

Question 31

energy production in bacteria

Answer 31

- in forms of ATP and NADH from glucose using 3 major pathways → glycolysis, TA cycle and PPP

Question 32

glycolysis

Answer 32

- aerobic and anaerobic conditions | - yield 2 ATP, 2 NADH and 2 pyruvated molecules from 1 glucose molecule

Question 33

main processes of glycolysis

Answer 33

1. substrate-level phosphorylation → transfer of P groups from ATP to glucose 2. breakdown of six-carbon glucose into 2 3-carbon molecules 3. transfer of 2 electrons to coenzyme NAD 4. capture of energy in ATP molecules

Question 34

Krebs cycle

Answer 34

- acetyl groups are oxidized to carbon dioxide - hydrogen atoms are removed → electrons transferred to coenzymes (elec. carriers) - hydrogens combined with oxygen to form water - ONLY under aerobic conditions - more energy than from glycolysis - aerobic metabolism can produce 38 ATP molecules from glucose - 19 times more than anaerobic metabolism

Question 35

main processes of krebs cycle

Answer 35

1. oxidation of carbon 2. transfer of electrons to coenzymes 3. capture of energy in ATP molecules

Question 36

importance of TCA cycle

Answer 36

- most efficeint mechanism for ATP - final common pathway for complete oxidation of amino acids, fatty acids and carbohydrates - key intermediates for ultimate synthesis of AAs, lipids, purines and pyrimidines

Question 37

PPP

Answer 37

- along with glycolysis - glucose and 5 carbon carbohydrates are brokes down - provide nucleic acid precursors and reducing power in form of NADPH - PPP → 1 ATP molecule for each oxidized glucose molecule

Question 38

bacterial cell division

Answer 38

by binary fission

Question 39

bacterial growth

Answer 39

- reproduce asexually → simple transverse binary fission - numbers increase logarithmically (n=2g) - rime for reprod. cycle = generation time → can vary - fast-growing bacteria have a generation time of 15-30min in vitro but more in vivo - obligate anaerobes grow much more slowly than aerobes → in vitro as well - tuberculosis bacs have an in vitro generation time of 12-24h - depends on nutrient content of medium

Question 40

phases of bacterial growth

Answer 40

A. lag phase → adaptation of bacteria to medium → no division → increase in bacterial mass per unit of volume → no increase in cell count B. directly into c-phase C. division of bacteria fast → cell count increases logarithmically up to 10 hoch 9 /ml D. division slows down E. division slows down even more → nutrients already used → toxins → exhaustion of nutrients and increasing concentration of toxic metabolites F. bacs die