The document summarizes centrosomes and centrioles. It discusses that centrosomes are located near the nucleus and are responsible for cell division, cytokinesis, and cytoskeleton formation. Within centrosomes are centrioles, which are made up of nine groups of microtubules arranged in a ring. Centrioles play important roles in cell division through organizing the mitotic spindle, cellular organization by organizing microtubules, and formation of cilia and flagella. Centriole duplication is coupled with the cell cycle and centrosome duplication occurs in early S phase through assembly of a new procentriole next to each parental centriole.
Describe the nonmembranous organelles of a typical cell with their structure and specific functions.
Summarize the process of protein synthesis.
Presaented by-
Dr. Subarna Das
Resident, Dept. of Anatomy, BSMMU
Guided by-
Dr. Zinnat Ara Yasmin
Asst. Prof, Dept. of Anatomy, BSMMU
Ribosomes are organelles found in all cells that synthesize proteins. They consist of RNA and proteins and exist as smaller and larger subunits. Ribosomes were discovered in 1950 and can be seen under electron microscopes. They translate genetic information from mRNA into amino acid chains. Recent research has provided new insights into ribosome structure and function and how they play a role in certain diseases.
This document provides an overview of cellular biology and the history of cell discovery. It discusses how:
1) Robert Hooke first observed cells in 1663 when examining cork under a microscope.
2) In the 1830s, botanist Schleiden and zoologist Schwann independently developed cell theory, establishing that organisms are composed of distinct cellular units.
3) Advances in microscopy, including electron microscopy in the 1950s, have driven discoveries like DNA structure and greatly increased understanding of cellular structures and functions.
This document summarizes key concepts about cell structure and function from a biology textbook. It discusses the plasma membrane and how it is selectively permeable, allowing passage of some molecules via diffusion or transport proteins. Transport can occur through passive diffusion down a concentration gradient or active transport against a gradient using carrier proteins like the sodium-potassium pump. The document also describes osmosis and transport of molecules into and out of cells through endocytosis and exocytosis.
The document summarizes centrosomes and centrioles. It discusses that centrosomes are located near the nucleus and are responsible for cell division, cytokinesis, and cytoskeleton formation. Within centrosomes are centrioles, which are made up of nine groups of microtubules arranged in a ring. Centrioles play important roles in cell division through organizing the mitotic spindle, cellular organization by organizing microtubules, and formation of cilia and flagella. Centriole duplication is coupled with the cell cycle and centrosome duplication occurs in early S phase through assembly of a new procentriole next to each parental centriole.
Centrosomes play roles in regulating the cell cycle checkpoint responses to DNA damage. Centrosomes contain centrioles and help regulate the G2/M transition under normal conditions through proteins like Cdc25, Aurora-A, and Chk1. In response to DNA damage, the Chk1 protein is activated and prevents phosphorylation of Cdc25, inhibiting progression through G2/M. Centrosome amplification can occur in response to DNA damage and impaired DNA repair, leading to chromosomal instability and potential tumorigenesis. Mechanisms of centrosome amplification include overreplication within a cell cycle or failures in cell division coupled with DNA and centrosome overreplication.
Centrioles are cylindrical structures found in animal cells composed of nine triplets of microtubules arranged in a 9+3 pattern. They are located in the centrosome and replicate during cell division to form two centrosomes that help organize the mitotic spindle. In plant cells, centrosomes are present but centrioles are absent. Centrioles also function as basal bodies to form cilia and flagella and help determine cell polarity.
The document summarizes centrosomes and centrioles. It discusses that centrosomes are located near the nucleus and are responsible for cell division, cytokinesis, and cytoskeleton formation. Within centrosomes are centrioles, which are made up of nine groups of microtubules arranged in a ring. Centrioles play important roles in cell division through organizing the mitotic spindle, cellular organization by organizing microtubules, and formation of cilia and flagella. Centriole duplication is coupled with the cell cycle and centrosome duplication occurs in early S phase through assembly of a new procentriole next to each parental centriole.
Describe the nonmembranous organelles of a typical cell with their structure and specific functions.
Summarize the process of protein synthesis.
Presaented by-
Dr. Subarna Das
Resident, Dept. of Anatomy, BSMMU
Guided by-
Dr. Zinnat Ara Yasmin
Asst. Prof, Dept. of Anatomy, BSMMU
Ribosomes are organelles found in all cells that synthesize proteins. They consist of RNA and proteins and exist as smaller and larger subunits. Ribosomes were discovered in 1950 and can be seen under electron microscopes. They translate genetic information from mRNA into amino acid chains. Recent research has provided new insights into ribosome structure and function and how they play a role in certain diseases.
This document provides an overview of cellular biology and the history of cell discovery. It discusses how:
1) Robert Hooke first observed cells in 1663 when examining cork under a microscope.
2) In the 1830s, botanist Schleiden and zoologist Schwann independently developed cell theory, establishing that organisms are composed of distinct cellular units.
3) Advances in microscopy, including electron microscopy in the 1950s, have driven discoveries like DNA structure and greatly increased understanding of cellular structures and functions.
This document summarizes key concepts about cell structure and function from a biology textbook. It discusses the plasma membrane and how it is selectively permeable, allowing passage of some molecules via diffusion or transport proteins. Transport can occur through passive diffusion down a concentration gradient or active transport against a gradient using carrier proteins like the sodium-potassium pump. The document also describes osmosis and transport of molecules into and out of cells through endocytosis and exocytosis.
The document summarizes centrosomes and centrioles. It discusses that centrosomes are located near the nucleus and are responsible for cell division, cytokinesis, and cytoskeleton formation. Within centrosomes are centrioles, which are made up of nine groups of microtubules arranged in a ring. Centrioles play important roles in cell division through organizing the mitotic spindle, cellular organization by organizing microtubules, and formation of cilia and flagella. Centriole duplication is coupled with the cell cycle and centrosome duplication occurs in early S phase through assembly of a new procentriole next to each parental centriole.
Centrosomes play roles in regulating the cell cycle checkpoint responses to DNA damage. Centrosomes contain centrioles and help regulate the G2/M transition under normal conditions through proteins like Cdc25, Aurora-A, and Chk1. In response to DNA damage, the Chk1 protein is activated and prevents phosphorylation of Cdc25, inhibiting progression through G2/M. Centrosome amplification can occur in response to DNA damage and impaired DNA repair, leading to chromosomal instability and potential tumorigenesis. Mechanisms of centrosome amplification include overreplication within a cell cycle or failures in cell division coupled with DNA and centrosome overreplication.
Centrioles are cylindrical structures found in animal cells composed of nine triplets of microtubules arranged in a 9+3 pattern. They are located in the centrosome and replicate during cell division to form two centrosomes that help organize the mitotic spindle. In plant cells, centrosomes are present but centrioles are absent. Centrioles also function as basal bodies to form cilia and flagella and help determine cell polarity.