Bacterial metabolism refers to the biochemical reactions that occur in bacteria, focusing on substrate breakdown to generate energy. There are two main types of bacterial nutrition: autotrophic bacteria can synthesize their own food through photosynthesis or chemosynthesis, while heterotrophic bacteria rely on other organisms for nutrition as parasites or saprophytes. Bacterial growth occurs through binary fission, where a single bacterial cell divides into two genetically identical daughter cells.

2.  Metabolism refers to all the biochemical reactions that occur in a cell or
organism. The study of bacterial metabolism focuses on the chemical
diversity of substrate oxidations and dissimilation reactions (reactions
by which substrate molecules are broken down), which normally function
in bacteria to generate energy.
Metabolism
– Sum up all the chemical processes that occur within a cell
1. Anabolism: Synthesis of more complex compounds and use of energy
2. Catabolism: Break down a substrate and capture energy

4. – Autotroph:
Photosynthetic bacterial
Chemoautotrophic bacteria
– Heterotroph:
Parasite
Saprophyte

5.  The bacterial growth curve represents the
number of live cells in a bacterial
population over a period of time. There are
four distinct phases of the growth curve: lag,
exponential (log), stationary, and death. The
initial phase is the lag phase where bacteria
are metabolically active but not dividing.

6.  Bacterial growth is proliferation of bacterium into two daughter
cells, in a process called binary fission. Providing no event
occurs, the resulting daughter cells are genetically identical to
the original cell. Hence, bacterial growth occurs. Both daughter
cells from the division do not necessarily survive. However, if the
number surviving exceeds unity on average, the bacterial
population undergoes exponential growth.
 The measurement of an exponential bacterial growth curve in
batch culture was traditionally a part of the training of all
microbiologists; the basic means requires bacterial enumeration
(cell counting) by direct and individual (microscopic, flow
cytometry[1]), direct and bulk (biomass), indirect and individual
(colony counting), or indirect and bulk (most probable
number, turbidity, nutrient uptake) methods. Models reconcile
theory with the measurements

7.  The nutrition in bacteria is mainly
autotrophic and heterotrophic.
 Phototrophic bacteria contain various
pigments to synthesize their own food, while
heterotrophic bacteria are dependent on
other organisms for food.
 Parasitic bacteria fulfil their nutrition needs
or requirements from the host cell.

11. Glycolysis occurs in the cytoplasm of
plant and animal cells
The main purpose of glycolysis is to
break glucose (a 6 carbon sugar) into
2 pyruvate molecules (a 3 carbon
molecule)
ATP is required in glycolysis and a
total of 2 ATP are converted into ADP
+ Pi

12. 1. Glucose
2. ATP
**Note: No oxygen required = anaerobic!

13. 1. Pyruvate
2. ATP
3. NADH

14. Result:
2 pyruvate
2 NADH
Net 2 ATP

15. The glucose is converted through a
series of steps to fructose-1,6-
diphosphate
Diphosphate ‘aka 2 phosphates’
means that 2 phosphate groups have
been added
Where do those phosphates come
from? ATP
Therefore, 2 ATP have been used up
Note: enzymes are responsible for
all these conversions!

16.  The fructose-1,6-diphosphate is then
converted to 2 G3P molecules
 G3P = glyceraldehyde 3-phosphate
 An H atom (carrying 1 proton & 2 electrons)
is picked up from each G3P atom (2 are
produced) and picked up by a
coenzyme/electron carrier NAD+
 Since NAD+ is gaining electrons it is REDUCED
(GER!) to NADH (a proton H+ is left over)
 Each G3P is then converted to a molecule of
pyruvate (pyruvic acid), a reaction which
requires the use of 2 ATP but produces 4 ATP
= net 2 ATP

18.  Intermediate step between glycolysis and the
kreb’s cycle

19. Location = Mitochondrial matrix
Its aerobic,  requires oxygen
Net 0 ATP
Pyruvate molecules transported
from cytoplasm to mitochondria
Converts each pyruvate (3C) into
acetyl coenzyme A (2C)
2 CO2 released (1 from each
pyruvate)
2 NAD+ reduced to NADH

20. pyruvate + NAD + CoA  acetyl-CoA + NADH + CO2
(2 pyruvate = 2 NADH and 2 CO2)
**CoA = coenzyme A. It is important because it
activates pyruvate

21.  Acetyl-CoA is ready to enter the Kreb’s cycle
 Kreb’s cycle occurs in the mitochondrial
matrix
 It is aerobic
 Net +2 ATP
 It is a CYCLE!, begins and ends with the
same compound (oxaloacetate)
 First compound to form via acetyl-CoA
entering is citric acid (citrate)

22. 2-C Acetyl-CoA
enzyme
4-C oxaloacetate (in mitoch.)
6-C citric acid
CoA recycled
2 CO2 molecules split off
4-C succinate (converted back to oxaloacetate)
This cycle turns twice for every glucose
molecule oxidized. (remember 1 glucose  2
pyruvate  2 acetyl-CoA  2 turns needed)

23.  Per acetyl-CoA
 3 NADH
 1 FADH2
 1 ATP
 2 CO2
 Per glucose
 6 NADH
 2 FADH2
 2 ATP
 4 CO2