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Franklin Highschool Vaden Mid term study guide

Terms in this set (97)

Plasma membrane is made primarily of phospholipids. Phospholipids have a polar, hydrophillic

(water-loving) phosphate head and two nonpolar, hydrophobic fatty acid tails. Allows substances

in/out of the cell.

Most of the functions of a eukaryotic cell are controlled by the nucleus.

The nucleus contains the DNA (held in the nucleoplasms). When the cell is not dividing the DNA

is in the form of chromatin (threadlike material). When a cell is about to divide, the chromatin

condenses to form chromosomes.

Nuclear envelope- double membrane surrounding the nucleus.

Nucleolus is the denser area of the nucleus. It is the side where DNA is concentrated when it is in

the process of making ribosomal RNA.

Mitochondria are tiny organelles that transfer energy from organic molecules to ATP.

Highly active cells, such as muscle cells, can have hundreds of mitochondria (energy needed).

Chloroplasts- involved in photosynthesis- only in plants.

Ribosomes- Small, roughly spherical organelles that are responsible for building protein. They are

made of protein and RNA molecules.

ER is a system of membranous tubes and sacs, called cisternae.

The ER functions primarily as an intracellular highway, a path along where molecules move from

one part of the cell to another.

There are two types of ER: rough and smooth.

The two types of ER are thought to be continuous.

Rough ER is most abundant in cells that produce large amounts of protein for export, such as

cells in digestive glands and antibody-producing cells.

Smooth ER- lacks ribosomes and has a smooth appearance. Smooth ER builds lipids such as


The Golgi apparatus is another system of flattened, membrane sacs.

The stacked membranes modify the vesicle contents as they move along.

Vesicles are small, spherically shaped sacs that are surrounded by a single membrane and are

classified by their contents. They often merge with the plasma membrane, and release their

contents to the outside of the cell.

Lysosomes- are vesicles that bud from the Golgi apparatus and contain digestive enzymes.

These enzymes can break down large molecules, such as preteins, nucleic acids, carbohydrates,

and phospholipids.

The cytoskeleton is a network of thin tubes and filaments that crisscrosses the cytosol. They give

shape and support to the cell. Also acts as a system of internal tracks on which items move

around inside the cell.

Microtubules- hollow tubes made of a protein called tubulin. They hold organelles in place,

maintain a cell's shape, and act as tracks that guide organelles and molecules as they move

within the cell.

o Microfilaments- fine, long thread of beadlike protein actin. They contribute to cell


Cilia and flagella- hair-like structures that extend from the surface of the cell. They assist in

movement. Cilia are short and are present in large numbers. Flagella are longer and are far less

numerous on the cell where they occur. Cilia- protists, flagella- sperm.

Centrioles- consist of two short cylinders of microtubules. They occur in animal cells, where they

organize the microtubules of the cytoskeleton during cell division. Plant cells lack centrioles.