The Cell Cycle

Basic Understanding Structure – An arrangement or organization of parts to form an organ, system, or living thing. Characteristics – pertaining to, constituting, or indicating the character or peculiar quality of a person or thing

Basic Understanding Response –any behavior of a living organism that results from an external or internal stimulus. Stimulus - Something that can elicit or evoke a physiological response in a cell, a tissue, or an organism Species –composed of related individuals that resemble one another, are able to breed among themselves

Basic Understanding Development – the act or process of growth or progress Function – to perform a specified action or activity; work Mobility – The ability to move from place to place, job to job, or level to level.

Basic Understanding Extinction – a coming to an end or dying out Hierarchy –any organized system of things ranked one above another in successive order

Robert Hooke English Naturalist Was the first to use the term cell. Was looking at CORK under a compound microscope.

What is a cell? It is the smallest unit of life that carries out function

Cells (basic unit of life) Hierarchy Cell Cells (basic unit of life) Tissues (A group of cells performing a similar function) Organs (A group of tissues performing a similar function) Organ System (A group of organs performing a similar function) Organism An individual living thing made up of smaller parts that work together (You and Me)

The Cell Theory All living things are made up of 1 or more cells The cell is the basic unit of structure, function, and organization in all living things. Cells come from other preexisting cells

Somatic Cells - any cell of a living organism other than the reproductive cells. Genetics - is the study of genes, genetic variation, and heredity in living organisms. 

Francesco Redi – The Italian Doctor It was previously thought that maggots spontaneously grew. Redi disproved this theory. He took 8 jars of rotting meat and covered 4 with muslin (fabric). The jars with muslin developed no maggots but the open jars had maggots. This is important because cells come from other cells.

Prokaryote Are unicellular – 1 Have no formed nucleus Bacteria are prokaryotes

Eukaryote Have a Nucleus Are very organized. Can be singular or multi-cellular. All living things, except bacteria, are made of eukaryotic cells

Fun Facts The human body has more than 200 kinds of cells The average adult body has 50 to 100 trillion cells

Homeostasis Homeostasis refers to the ability of the body or a cell to seek and maintain a condition of equilibrium or stability within its internal environment when dealing with external changes. 

What’s Inside? Organelles tiny structures within a cell that perform specific jobs to keep the cell alive

Important Organelles Cytoplasm - gel-like material that fills the inside of cells Helps give the cell its shape Cytoplasm

Important Organelles – Continued… Cell Membrane - protects cell and controls what enters and leaves the cell. Cell Membrane

Important Organelles – Continued… Nucleus - directs cell activities (brain) - Contains the genes of the cell Nucleus

The Nucleolus Nucleolus- Contains RNA- Job - to produce Ribosomes The nucleolus is located in the nucleus

Important Organelles – Continued… Chromosomes - contains genetic information (DNA) - Every cell has chromosomes - Humans have 46 chromosomes in each nucleus except in gamete cells. The sex chromosomes are classified as either x or y - Females have two x chromosomes XX - Males have a x and a y chromosomes XY

Chromatin – Chromatid - Chromosomes Chromatin is the thread like combination of DNA and protein During cell division DNA replicates to produce two identical copies which connect at a centromere forming a sister chromatid pair appearing as an x shape.

Chromatin – Chromatid - Chromosomes During mitosis the chromatid condense even more forming chromosomes. When a cell divides, the sister chromatids separate, and each daughter cell receives one of the strands. The chromatid then decondenses into a long single chromatin strand.

DNA Each nucleotide contains a phosphate group, a sugar group and a nitrogen base. The four types of nitrogen bases are adenine (A), thymine (T), guanine (G) and cytosine (C). The order of these bases is what determines DNA's instructions, or genetic code. Deoxyribonucleic acid or DNA is a molecule that contains the instructions an organism needs to develop, live and reproduce. DNA is made up of molecules called nucleotides.

RNA Short for ribonucleic acid. The nucleic acid that is used in key metabolic processes for all steps of protein synthesis in all living cells and translates the genetic code. Unlike double-stranded DNA, RNA consists of a single strand of nucleotides, and it occurs in a variety of lengths and shapes. Thymine is replaced with Uracil

Important Organelles – Continued… Endoplasmic Reticulum (ER) –Transports proteins to other parts of the cell ER

Important Organelles – Continued… Ribosome - Sites of protein synthesis (makes proteins)

Important Organelles – Continued… Mitochondria - the powerhouse of the cell (converts food and oxygen into energy for the cell) Mitochondria

Important Organelles – Continued… Golgi Apparatus aka Golgi Bodies – Stores and packages proteins Golgi Body

Important Organelles – Continued… Lysosome – Destroys and digests old organelles and waste Lysosome

Important Organelles – Continued… Vacuole - storage of food and water - Generally bigger in plants Vacuole

Cells

Plant Cells Have two main differences from animal cells 1. Cell wall = a tough, usually flexible but sometimes fairly rigid layer that surrounds a cell 2. Chloroplasts = organelles found in plant and other eukaryotic organisms that conduct photosynthesis

Important Organelles – Continued… Cell Wall - supports and protects PLANT cells (not found in animal cells) Cell Wall

Important Organelles – Continued… Chloroplast - takes energy from the sun and makes food for the PLANT cell (not found in Animal Cells) Chloroplast