The document discusses the cell nucleus. It begins by defining the nucleus as a membrane-bound organelle found in eukaryotic cells that contains the cell's hereditary information and controls its growth and reproduction. It then describes the key components of the nucleus, including the nuclear envelope, nucleoplasm, nucleolus, and nuclear pores. The document also explains the nucleus's role in regulating protein synthesis and packaging DNA into chromatin and chromosomes. In addition, it discusses how the nucleus and nuclear pores control the passage of molecules between the nucleus and cytoplasm.

1. Cell biology
and
Biochemistry
Name: Mili Bhardwaj
Registration number:
16BCB0076
2/12/2018
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Cell nucleus
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3. Introduction
• In cell biology, the nucleus is a membrane-enclosed organelle
found in eukaryotic cells.
• Eukaryotes usually have a single nucleus.
• But a few cell types, such as mammalian red blood cells, have
no nuclei, and a few others have many.
• Human skeletal muscle cells have more than one nucleus, as
do eukaryotes like fungi.
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An introduction to cell nucleus
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4. The cell nucleus is a
membrane bound
structure that
contains the cell's
hereditary
information and
controls the cell's
growth and
reproduction. It is
the command center
of a
eukaryotic cell and
is commonly the
most
prominent organelle
in a cell.
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Inner view of Cell Nucleus
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5. Distinguishing characteristics• bound by a double membrane called the nuclear envelope
• the nuclear envelope consists of phospholipids that form a
lipid bilayer.
• The nucleus is the organelle which houses chromosomes.
• The nuclear envelope is connected with the endoplasmic
reticulum (ER)in such a way that the internal compartment
of the nuclear envelope is continuous with the lumen of the
ER.
• Chromosomes consist of DNA, which contains heredity
information and instructions for cell growth, development, and
reproduction.
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6. Nucleoplasm
• Nucleoplasm is the gelatinous substance within the nuclear
envelope.
• composed mainly of water with dissolved salts, enzymes, and
organic molecules suspended within.
• Nucleoplasm also supports the nucleus by helping to maintain
its shape.
• Substances are exchanged between the cytoplasm and
nucleoplasm through nuclear pores.
• Additionally, nucleoplasm provides a medium by which
materials, such as enzymes and nucleotides (DNA and RNA
subunits), can be transported throughout the nucleus.
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Components of the Cell
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7. Nucleolus
• membrane-less structure composed of RNA
and proteins called the nucleolus.
• contains nucleolar organizers, which are parts of
chromosomes with the genes for ribosome synthesis on them.
• helps to synthesize ribosomes by transcribing and assembling
ribosomal RNA subunits.
• These subunits join together to form a ribosome during
protein synthesis.
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Components of the Cell
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8. Protein synthesis
• The nucleus regulates the synthesis of proteins in the
cytoplasm through the use of messenger RNA (mRNA)
• Messenger RNA is a transcribed DNA segment that serves as a
template for protein production
• It is produced in the nucleus and travels to the cytoplasm
through the nuclear pores of the nuclear envelope.
• Once in the cytoplasm, ribosomes and another RNA molecule
called transfer RNA work together to translate mRNA to
produce proteins.
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Functions
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Functions
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10. Chromatin and chromosomes• Packed inside the nucleus of every human cell is nearly 6 feet
of DNA, which is divided into 46 individual molecules, one for
each chromosome and each about 1.5 inches long.
• Packing all this material into a microscopic cell nucleus is an
extraordinary feat of packaging.
• For DNA to function, it can't be crammed into the nucleus like
a ball of string. Instead, it is combined with proteins and
organized into a precise, compact structure, a dense string-
like fiber called chromatin.
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Functions
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Functions
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12. Nuclear pores
• The nuclear envelope is perforated with holes called nuclear
pores.
• These pores regulate the passage of molecules between the
nucleus and cytoplasm, permitting some to pass through the
membrane, but not others.
• Building blocks for building DNA and RNA are allowed into the
nucleus as well as molecules that provide the energy for
constructing genetic material.
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14. Applications of Cell Nucleus
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Applications
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15. Application od Cell Nucleus
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