The animal Cell

What is a cell?

“cell” is! The Cell - basic unit of structure & function in the organism; most cell are vary small and invisible without using a microscope.

Cell Theory 1. Every living organism is composed of cells. 2. Every cell in an organism produced by anther cell.

Cell Structure

Cell Membrane Structure: Surround the parts of cell together. Function (job): Controls the movement of material into and out of cell.

Cytoplasm Structure: Substance between the cell membrane and the nucleus.(Everything within the cell membrane which is not the nucleus is known as the cytoplasm). Makes up most of the mass of many cell. Function (job): Different cell material are produced by cytoplasm.

Cytoplasm Cytosol is the jelly-like mixture in which the other organelles are suspended, so cytosol + organelles = cytoplasm.

Nucleus Structure: Usually round/oval Near center The nucleus separated from the cytoplasm by a thin membrane is called nuclear membrane.

Nucleus Function (job): Controls cell activities

Mitochondria Structure: Rod shaped

Mitochondria Function (job): Release energy & it is called (Power house of cell)

Ribosomes Structure: Tiny particle, so small, they can see only with an electron microscope.

Ribosomes Function (job): Site of Protein synthesis because it consisting of RNA and protein.

Endoplasmic Reticulum Structure: Like tubes Smooth ER - no ribosomes attached Rough ER - ribosomes are attached

Endoplasmic Reticulum Function (job): Transports materials “intracellular

Golgi Bodies Structure: Series of flattened sacs

Golgi Bodies Function (job): Processes, packages and secretes material Materials that are transported by the ER usually stop first at the Golgi bodies where they are stored or altered before moving to other parts of the cell

Lysosomes Structure: Round organelles surrounded by a membrane. Function (job): Contains powerful digestive enzymes

Vacuoles Structure: Fluid-filled sacs that float in the cytoplasm

Vacuoles Function (job): Stores water and food materials Stores waste and helps the cell get rid of waste

Cell types: Prokaryotic cell - very simple; no membrane-bound structures (ex: bacteria) Eukaryotic cell - more advanced; has (ex: animal cells, plant cells)

Organization of Living Things Five main levels of organization 1. Cell 2. Tissue 3. Organ 4. Organ System 5. Organism

Tissue Example: Muscle Tissues are made of specialized cells.

Organ Examples: Heart, Lung, Brain Found in both plants and animals. Composed of tissue that is organized into groups that work together to perform special functions.

Organ System Example: Circulatory System A group of organs that work together.

10 Organ Systems in complex organisms (humans, dogs, birds, etc.) 1. Circulatory 2. Digestive 3. Nervous 4. Respiratory 5. Skin 6. Skeletal 7. Muscular 8. Reproductive 9. Excretory 10.Endocrine

ORGANISMS Different organ systems work together to keep the organism alive.

QUESTION: Classify the following as a tissue, organ, or organ system. a. Brain, spinal cord, and nerves b. Heart c. Group of muscle cells

QUESTION: Can a single-celled organism contain tissue? Explain.

QUESTION: Give one example of each: a. Cell c. Tissue b. Organ d. Organism

Cell Division

Cell Division The cells in your body are constantly changing. Most new cells replace damaged or dead cells. These new cells are made during a process called cell division. When cell division takes place two identical cells are produced.

Cell Division In single celled organisms, cell division results in the formation of two new organisms. Dividing Paramecium

Cell Division Feeling Fine In many celled organisms, cell division increases the number of cells making up the organism. As the cells increase in number, the organism grows. Feeling Fine

This cycle may take a few hours or a few days! Cell Cycle The cell grows and develops. The cell divides. The cell prepares for division. This cycle may take a few hours or a few days!

Cell Cycle of Human Liver Cell Mitosis: Cell Division 1 hour Growth 9 hours Preparation for Division 2 hours DNA Replication 10 hours

This process by which a cell’s nucleus divides into two identical nuclei is called Mitosis

Mitosis Mitosis occurs in several phases. Most of a cell’s life is spent in the growth and development phase, called ‘interphase.’

Interphase What's Happening? The cell is making enough protein, mitochondria, and other substances for two cells. In the nucleus, each chromosome is forming an exact copy of itself. In animal cells, two pairs of centrioles are forming in the cytoplasm.

Prophase What's Happening? The nuclear membrane dissolves. The centrioles migrate to opposite sides of the cell. Spindle fibers form between the centrioles. Chromatid pairs are pulled to the center of the cell by the spindles.

Metaphase What's Happening? The chromosomes align across the center of the cell. Each chromosome attaches to a spindle fiber at its centromere.

Anaphase What's Happening? The centromeres split and the chromatids become two identical chromosomes. The spindle fibers shrink, pulling the chromosomes to opposite sides of the cell. The cell stretches out to prepare for division.

Telophase What's Happening? The chromosomes reach opposite ends of the cell. The spindles disintegrate. A nuclear membrane forms around each set of chromosomes, forming two new nuclei. A furrow forms in the cell membrane, deepens, and divides the cell completely.

Mitosis in Plants ....is different! Plants do not have centrioles. But they do have spindle fibers. The rigid cell wall can’t form a furrow in the middle, so a cell plate forms across the middle.

Mitosis in Plants ....is different! After the cell divides into two new cells, each forms its own cell wall.

During what phase of mitosis does a cell divide into two new cells? QUESTION: During what phase of mitosis does a cell divide into two new cells? Answer: During telophase!

How does mitosis differ in plants and animals? QUESTION: How does mitosis differ in plants and animals? Answer: Plants do not have centrioles. Plants form a cell plate before dividing.