Biology Ch 8 Cell function lesson 8.2

Cytoplasm

the portion of the cell outside the nucleus

Organelles are

like tiny organs within cells.

nucleus

contains nearly all the cell's DNA and, with it, the coded instructions for making proteins and other important molecules. Only eukaryotic cells have nucleus. In prokaryotic cells, DNA is found in the cytoplasm.

RNA

A single-stranded nucleic acid that passes along genetic messages and moves with other molecules in and out fo the nucleus to the rest of the cell

chromosomes

carry the cell's genetic information, are also in the nucleus. Most of the time threadlike chromosomes are spread in the nucleus in the form of chromatin

chromatin

a complex of DNA bound to proteins

what is one of the most important jobs carried out in the cell?

making proteins

where are proteins assembled?

ribosomes

ribosomes

small particles of RNA and protein found throughout the cytoplasm in all cells (eukaryotes and prokaryotes). They produce proteins by following coded instructions that come from DNA.

Endoplasmic Reticulum (ER)

A system of membranes that is found in a cell's cytoplasm and that assists in the production, processing, and transport of proteins and in the production of lipids.

Proteins made on the ER are...

those that will be released or secreted from the cell, many membrane proteins and proteins destined for other specialized locations in the cell.

rough ER

portion of the ER involved in the synthesis of proteins, it has ribosomes on its surface.

Smooth ER

That portion of the endoplasmic reticulum that is free of ribosomes. Synthesis of lipids and carbohydrates and detoxification of drugs

Golgi apparatus

A stack of flattened membranes that modifies and packages proteins from the rough ER for storage in the cell or release from the cell (In eukaryotic cells)

Ribosomes, the endoplasmic reticulum an the Golgi apparatus

synthesize, modify, package and ship proteins

Vacuoles

Store. Cell organelle, large sack membrane enclosed structures that stores materials such as water, salts, proteins, and carbohydrates

vacuoles in plant cells

A large, single, central region that stores water and dissolved salts
Provides turgor pressure inside the plant which helps support heavy leaves and flowers

contractile vacuole

saclike organelles that expand to collect excess water and contract to squeeze the water out of the cell

Vesicles

small membrane enclosed structures that store and move materials between cell organelle and to and from the cell surface

lysosomes

Clean. small organelles filled with enzymes to break down lipids, carbohydrates, and proteins into small molecules that can be used by the rest of the cell.

cyto

cells (prefix)

Cytoskeleton

A network of protein filaments that holds the cell together, helps the cell to keep its shape, and aids in movement

Microtubules

A hollow rod composed of tubulin proteins and help maintain cell shape and help in cell division with mitotic spindle and help build projections from the cell surface known as cilia and flagella that help cells swim through liquide.

Microfilaments

Long, thin fibers of protein called actin that function in the movement and support of the cell. Part of the cytoskeleton.

Chloroplast

Equivalent to solar power plantes. Organelle found in cells of plants and some other organisms that captures the energy from sunlight and converts it into chemical energy stored in food in photosynthesis. 2 membranes surround chloroplast.

chlorophyll

Green pigment in chloroplasts that absorbs light energy used to carry out photosynthesis

Mitochondria

Power plants of the cell. They convert the chemical energy stored in food molecules into compounds that are more convenient for the cell to use. 2 membranes surround the mitochondria, the inner membrane is folded up inside the organelle.

How is mitochondrial DNA inherited?

from the mother, they originate from the cytoplasm of the ovum

Lynn Margulis

Developed the Endosymbiotic Theory - chloroplasts and mitochondria are descended from free living prokaryotes that were engulfed by ancestral eukaryotes.

cell wall

A rigid structure that surrounds the cell membrane and provides support to the cell, most prokaryotes and many eukaryotes have cell walls although animal cells do not.

lipid bilayer (cell membrane)

thin, flexible double layered sheet around a cell; regulates what enters and leaves the cell. All cells have cell membrane

Lipids

Energy-rich organic compounds, such as fats, oils, and waxes, that are made of carbon, hydrogen, and oxygen.

selectively permeable

a property of cell membranes that allows some substances to pass through, while others cannot

fluid mosaic model of membrane structure

states that a membrane is a fluid structure with a "mosaic" of various proteins embedded in it