Page 17 - Cell biology PDC 2024

function is the supply and storage of energy for the cell. It also helps in
the process of apoptosis.

Structure:

• A mitochondrion contains two membranes with the outer layer
being smooth while the inner layer is marked with folding and
finger-like structures called cristae

• Between the membranes exists the matrix that contains various
enzymes of metabolic processes like Kreb’s cycle.

• In addition to these enzymes, mitochondria has DNA called
mtDNA that is coding for 10% of the proteins present in it

J) Chloroplasts

A chloroplast is a cell organelle known as a plastid, characterized by its
two membranes and a high concentration of chlorophyll .

Chloroplasts are highly dynamic—they circulate and are moved around
within plant cells, and occasionally pinch in two to reproduce.

Their behavior is strongly influenced by environmental factors like light
color and intensity.

Chloroplasts, like mitochondria, contain their own DNA.

Cell inclusions: Inclusions are intracellular non-living substances that are
not bound by membranes.

Ex:
 Glycogen is the storage form of glucose in animals and is found in
cells of muscles, and liver. Glycogen is an important source of
energy for the cell. The enzymes responsible for glycogenolysis
degrade glycogen into individual molecules of glucose and can be
utilized by multiple organs of the body

 Lipids are triglycerides, they are stored in specialized cells
(adipocytes) in the adipose tissue but also are located as individual
droplets in various cell type especially hepatocytes. Lipid yields
more calories per gram than carbohydrate. On demand, they serve
as a local store of energy and a source of short carbon chains that
are used by the cell in its synthesis of membranes.

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