THE CELL PARTS OF THE EUKARYOTIC CELL Mr. Zweig Life Science

Parts of the Eukaryotic cell  To survive, a cell must eat (get nutrients) and go to the bathroom (eliminate waste)  This is done by the cell membrane.  The cell membrane controls what goes in and out of the cell and is said to be selectively permeable. It selects what is permeable (gets in)

Parts of the Eukaryotic cell THE CELL MEMBRANE

Parts of the Eukaryotic cell  phospholipids are fats with phosphorus and they make up much of the cell membrane.

Parts of the Eukaryotic cell  This is the lipid bilayer … it makes the cell membrane and must exist to keep water inside the cell and the cell in a water environment!

Parts of the Eukaryotic cell  The cell membrane is also composed of proteins!  The proteins are either peripheral (on the outside or inside layer), or integral (embedded in the lipid bilayer)!

Parts of the Eukaryotic cell  Notice the carbohydrates attached to outer proteins on membrane!  These can act as sites for viruses or hormones (chemical messengers) can attach  They also may be a site where cells hold together!

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Parts of the Eukaryotic cell ORGANELLES

The Cytoplasm  The cell membrane keeps inside the cell the Jell-O-like (gelatin) substance called the cytosol.  The region (area) of the cell between in nucleus and cell membrane is called the cytoplasm.

The Mitochondria  Scattered throughout the cytosol are large organelles called mitochondria.  This is the POWER HOUSE of the cell and makes ENERGY!!!!!

The Ribosomes  The most organelles found in many cells are the ribosomes!  Unlike most organelles, ribosomes do not have an outer membrane so they are found in BOTH prokaryotes and eukaryotes!  Ribosomes MAKE PROTEIN!!!!!!!!!!!!!!!!!!

The Ribosomes  Just remember: Ribosomes make proteins!  The ribosomes are located where they are needed. The ones that make proteins needed in the cytosol float free in the cytosol.  The ones that make proteins to be inserted into membranes or exported from the cell are made by those attached to another organelle called the endoplasmic reticulum.

The Endoplasmic Reticulum  The endoplasmic reticulum, abbreviated ER, is a system of tubules and sacs with membranes  There are 2 types of ER:  Ones with ribosomes on outside is the ROUGH ER  Ones without is the SMOOTH ER

The Endoplasmic Reticulum  The ER functions as an intracellular highway, it is the path molecules use from one part of the cell to another!  See the ribosomes (dots) on the rough ER!

The Golgi Apparatus  The golgi apparatus, is the part of the cell where things are processed, packaged, and secreted.  It is like the POST OFFICE  Here things are PACKAGED & SHIPPED!  They have membranes too  It works with ER closely

The Lysosomes  Lysosomes are small, round organelles that hold enzymes within a single membrane – they EAT THINGS UP  They digest old proteins, carbohydrates, lipids, DNA & RNA  They can digest old and aged organelles, as well as viruses and bacteria!  Common in animals, fungi, and algae, but are rare in plant cells.

The Cytoskeleton  The cytoskeleton is a network if long protein strands in the cytosol that helps a cell keep its shape and size just like the human skeleton,  These strands are not surrounded by membranes  Two major components of the cytoskeleton are microfilaments and microtubules

Cilia and Flagella  Cilia and flagella are hair-like organelles that extend from the surface of a cell and assist in movement  When present in large numbers they are called cilia  When long and less numerous they are called flagella.

Cilia and Flagella  Both cilia and microtubules have similar internal structure.  Notice the membrane and nine pairs of outer and pair of inner microtubules that form these organelles!

The Nucleus  The nucleus is usually the most prominent structure in a eukaryotic cell.  A double membrane called the nuclear envelope surrounds the nucleus.  Inside are fine strands of chromatin (combination of DNA & protein that form chromosomes)

The Nucleus  DNA makes RNA and sends it into the cytosol through small holes in the nuclear envelope called nuclear pores.  Most nuclei have at least one spherical nucleolus, the site where ribosomes are synthesized and sent through the nuclear pores

Parts of the Eukaryotic cell PLANT CELLS

Most of the organelles we looked at are in almost all eukaryotic cells! Plant cells have three extra structures: KNOW THESE FOR TESTS!!!!!!  They are cell walls, vacuoles, and chloroplasts.

The Cell Wall  Outside the cell membrane in a plant cell is a Hard cell wall.  Cell walls are made of cellulose a complex carbohydate  See the two membranes 

The vacuole  The vacuole is a fluid filled organelle that stores enzymes and waste.  Some vacuoles can take up 90% of a cell’s volume  Some waste inside can be toxic and used for protection against plant-eating animals!  Like a big WATER BALLOON

The Chloroplasts  Chloroplasts are organelles, like mitochondria and the nucleus that are surrounded by two membranes and contain DNA.  They have flattened sacs called thylakoids  Sunlight is converted in chloroplasts into chemical energy in a process called photosynthesis and this occurs in the thylakoids!

Parts of the Eukaryotic cell MULTICELLULAR ORGANIZATION

Tissues, Organs, and Systems  Cells are organized into tissues, or groups of cells that carry out a specific function  Several types of tissues that interact to perform a specific function, form an organ.  A system is a group of organs that work together to perform a set of related tasks  For example, the digestive system has the mouth, esophagus, stomach, intestines and others!

THE END Yeah!