HUMAN DNA

DNA- genetic information of the cell (Blueprint of Life) * NUCLEIC ACID *

Storing DNA

• Chromatin- uncoiled DNA (store this way during normal cell functions)

• Chromosomes- DNA coiled around proteins (stored this way when the cell reproduces)

In order for a cell to make a new cell it must replicate (copy) its

existing chromosomes• Replicated Chromosomes

– Sister Chromatids- exact copies of DNA

– Centromere- connects sister chromatids

Centromere

Karyotype

• Photograph of all chromosomes in a cell, arranged by size

Types of Chromosomes

• Homologous Chromosomes- two chromosomes that carry the same type of information, but are not identical

• Autosomes- non-sex chromosomes

• Humans: 22 pairs of autosomes + 1 pair of sex chromosomes = 23 pairs or 46 chromosomes

Cell Cycle- process where cells grow and divide

• Important: growth, wound healing, replace cells (old skin cells)….

Cell structures involved in reproduction

• Chromosomes

• Spindle- protein fibers that move chromosomes

• Centrioles- structures that anchor spindle at ends of the cell

NORMAL CELL LIFE CYCLE

• INTERPHASE– GROWTH – G1 – growth of organelles– SYNTHESIS – S – synthesis of new DNA– GROWTH – G2 – growth of proteins

• MITOSIS– division of duplicated DNA– PMAT – Prophase, Metaphase, Anaphase &

Telophase

• Prophase – Chromosomes present themselves; they become

visible.

• Metaphase– Chromosomes line up in the middle; on equator.

• Anaphase– Centromeres divide. Chromosomes move apart

• Telophase– Chromosomes uncoil, cytokinesis begins, and

becomes two cells.

Mitosis In Action!

• Mitosis

• Mitosis

CANCER – OUT OF CONTROL CELL GROWTH

• BENIGN or MALIGNANT – A difference in activity

• METASTASIS – Spread away from the site of origin

• Carcinoma, Sarcoma, Leukemia & Lymphoma