Bio 211 Cell Organelles

Rough ER

A network of interconnected membranous sacs in a eukaryotic cell's cytoplasm; covered with ribosomes that make membrane proteins and secretory proteins.

Mitochondria

Powerhouse of the cell, organelle that is the site of ATP (energy) production are large organelles with double membranes where cellular respiration (breaking down glucose to get energy) occurs 1. Energy from glucose is used to make ATP or adenosine triphosphate 2. cells use the ATP molecule for energy 3. More active cells like muscle cells have more mitochondria 4. Outer membrane is smooth, while inner membrane has long folds called cristae 5. Have their own DNA to make more mitochondria when needed

Transmembrane proteins

Proteins that pass through the cell membrane; allow communication & transport between intra/extracellular

Smooth ER

Ribosomes are not found on its surface. It contains collections of enzymes that perform specialized tasks including the synthesis of membrane lipids and the detoxification of drugs.

cytoplasm

The entire contents of the cell, exclusive of the nucleus, and bounded by the plasma membrane.

cilia

a hairlike projection from the surface of a cell

Nucleus

a part of the cell containing DNA and RNA and responsible for growth and reproduction

cell wall

a rigid structure that surrounds the cell membrane and provides support to the cell, made out of chittin in fungus and cellulose in plants

nucleolus

a small round body of protein in a cell nucleus, The organelle where ribosomes are made, synthesized and partially assembled, located in the nucleus, disapears during cell division

centromere

a specialized condensed region of each chromosome that appears during mitosis where the chromatids are held together to form an X shape

Endoplasmic reticulum

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

cell membrane

a thin membrane around the cytoplasm of a cell A. Separates the cytoplasm of the cell from its environment B.Protects the cell & controls what enters and leaves C. Cell membranes are selectively permeable only allowing certain materials to enter or leave D. Composed of a lipid bilayer made of phospholipid molecules

Eukaryote

an organism made up of cells that have a nucleus enclosed by a membrane, multiple chromosomes, and a mitotic cycle; eukaryotes include protists, animals, plants, and fungi but not archaea or bacteria

peripheral proteins

are not embedded in the lipid bilayer at all. Instead, the are loosely bound to the surface of the protein, often connected to integral proteins

phospholipid molecules

compose the membrane structure; have polar phosphate heads (hydrophilic), and lipid non-polar tails (hydrophobic) The hydrophilic head of a phospholipid is polar & composed of a glycerol & phosphate group and points to the aqueous cytoplasm and external environment. The two hydrophobic tails are nonpolar point toward each other in the center of the membrane & are composed of two fatty acids

nuclear envelope

double membrane perforated with pores that control the flow of materials in and out of the nucleus

microtubules

hollow tubes of protein about 25 nanometers in diameter, support the cell and moves organelles within the cell

chromatin

long strands of DNA found in the eukaryotic cell nucleus; condense to form chromosomes

flagella

long, thin, whip-like structures, with a core of microtubules, that enable some cells to move

Lysosome

membrane-bound sac containing digestive enzymes that can break down proteins, nucleic acids, and polysaccharides, abundant in liver and kidney. Nor found in plant cells

Cytoskeleton

network of protein filaments within some cells that helps the cell maintain its shape and is involved in many forms of cell movement

Ribosomes

non membrane bounded organelles responsible for protein synthesis

centriole

one of two small cylindrical cell organelles composes of 9 triplet microtubules

Chloroplast

organelle found in cells of plants and some other organisms that captures the energy from sunlight and converts it into chemical energy

Prokaryotes

organisms that lack a membrane-bound nucleus and membrane-bound organelles

membrane proteins

proteins that function in transport, enzymatic activity, signal transduction, cell-cell recognition, intercellular joining, attachment to the cytoskeleton and extracellular matrix, located in cell membrane

Channel proteins

proteins that provide passageways through the membrane for certain hydrophilic (water-soluble) substances such as polar and charged molecules

Vacuoles

saclike structures that store materials such as water, salts, proteins, and carbohydrates

Cilia

short structures projecting from a cell and containing bundles of microtubules that move a cell through its surroundings or move fluid over the cell's surface

Golgi Apparatus

stack of membranes in the cell that modifies, sorts, and packages proteins from the endoplasmic reticulum

cytosol

the part of the cytoplasm that includes molecules and small particles, such as ribosomes, but not membrane-bound organelles, the aqueous part of the cytoplasm within which various particles and organelles are suspended

microfilaments

thinner, solid rods of protein that enable the cell to move or change shape when protein subunits slide past one another

Flagella

whiplike tails found in one-celled organisms to aid in movement