DNA Structure and Function

DNA-Introduction https://www.brainpop.com/health/geneticsgrowthanddevelopment/dna/

DNA- DeoxyriboNucleic Acid Located in most all cells Specifically in the nucleus Makes up chromosomes Controls all cell activities

DNA-Discovery James Watson American Biologist and Francis Crick English Physicist – put together the structure of DNA - model

DNA-Discovery

DNA-Strucure Shape is that of a Double Helix- “twisted ladder” Made up of: -Deoxyribose Sugar -Phosphate molecule -Nitrogen Bases

DNA Structure The basic unit or building block is called a Nucleotide It is made up of: - Deoxyribose Sugar - Phosphate Group - Nitrogen Base

DNA-Structure Sides of the ladder are made up of alternating molecules of: -Phosphate -Deoxyribose Sugar

DNA-Structure The middle or “rungs of the ladder” are made up of Nitrogen Bases There are FOUR different types of Nitrogen Bases They are joined by weak Hydrogen Bonds.

DNA-Structure Base Pair Rule: Adenine (A) bonds with Thymine (T) Cytosine (C) bonds with Guanine (G)

DNA Candy Model

DNA-Structure DNA “winds up” and condenses to make Chromosomes. Genes are segments of DNA located on specific sites on chromosomes that code for a specific Protein.

DNA Replication Process in which DNA makes an exact copy of itself Takes place in the Nucleus Provides a set of instructions for new cells –growth or healing

DNA-Replication STEPS: DNA unzips – hydrogen bonds between nitrogen bases are broken by an enzyme. Free nucleotides in nucleus line up with exposed nitrogen bases – helped by another enzyme Bonds are formed between sides and nitrogen bases leaving 2 DNA molecules each made up of one original strand and one newly formed strand. VIDEO: https://www.youtube.com/watch?v=5qSrmeiWsuc

DNA- Replication

Chromosomes Chromosomes are identified by their size, location of centromere and banding pattern.

Parts of a Chromosome Telomere – the end or tip of a chromosome Centromere – part of where spindle fibers attach Chromatid – one copy of a newly copied chromosome which is still joined to the original chromosome by a single centromere

Homologous Chromosomes

Human Chromosomes

Mitosis – Cell Division Why would a cell need to divide? What process would need to take place BEFORE cell division occurs? What type of cells undergo Mitotic Division? What does Mitosis mean?

Mitosis – Cell Division ANSWERS: Make more cells for growth or repair. Replication Body Cells or SOMA Cells – Asexual Reproduction “Mito” = thread-like “osis” = condition Let’s Take a Look!!

Mitosis Is a process where a single cell divides into two daughter cells division of the nuclear material occurs in eukaryotic cells: animal & plant Daughter cells are exact copies of the parent cells in number and kinds of chromosomes 2n--) 2n Video : Brain Pop https://www.brainpop.com/science/cellularlifeandgenetics/mitosis/

Mitosis – Plant Cells

Mitosis – Stages of

Inter - Between

Pro - First

Meta - MIddle

Ana - ???

Telo – End

Mitosis – Animal Cells

Mitosis Plant Cell

Mitosis Animal vs Plant

Quiz - Mitosis