Cells and Organelles

Organelles

membrane-enclosed compartments (subcellular structures)

Cell Fractionation

taking cells apart and separating the major organelles from one another

Prokaryotic Cell

a type of cell which has its DNA concentrated at the nucleoid, which is not surrounded by a membrane

Nucleoid

the area not enclosed by a membrane where the DNA is concentrated, in a prokaryotic cell

Eukaryotic Cell

a type of cell which has a true nucleus, and many organelles

Cytoplasm

the entire space between the nucleus and the plasma membrane

Plasma Membrane

the selective barrier which allows the sufficient passage of oxygen, nutrients, and wastes to service the entire volume of the cell at the boundary of the cell

Flagellum

locomotion organelle present in some animal cells; composed of membrane-enclosed microtubules

Centrosome

region where the cell's microtubules are initiated; in an animal cell, contains a pair of centrioles

Cytoskeleton

reinforces cell's shape, functions in cell movement; components made of protein (microfilaments, intermediate filaments, microtubules)

Microvilli

projections that increase the cell's surface area

Peroxisome

organelle with various specialized metabolic functions; produces hydrogen peroxide

Mitochondrion

organelle where cellular respiration occurs and most ATP is produced

Lysosome

digestive organelle where macromolecules are hydrolyzed

Golgi Apparatus

organelle active in synthesis, modification, sorting, and secretion of cell products

Ribosomes

nonmembranous organelles that make proteins, free in cytoplasm or bound to rough ER nuclear envelope

Chromatin

material consisting of DNA and proteins; visible as individual chromosomes in a dividing cell

Nucleolus

nonmembranous organelle involved in production of ribosomes; a nucleus has one or more nucleoli

Nuclear Envelope

double membrane enclosing the nucleus; perforated by pores, contiguous with ER

Cell Wall

outer layer that maintains cell's shape and protects cell from mechanical damage; made of cellulose, other polysaccharides, and protein

Plasmodesmata

channels through the cell walls that connect the cytoplasm of adjacent cells

Chloroplast

photosynthetic organelle, converts energy of sunlight to chemical energy stored in sugar molecules

Central Vacuole

prominent organelle in older plant cells, functions include storage, breakdown of waste products, hydrolysis of macromolecules; enlargement of vacuole is a major mechanism of plant growth

Endoplasmic Reticulum

network of membranous sacs and tubes; active in membrane synthesis and other synthetic and metabolic processes; has rough(ribosome-studded) and smooth regions

Vesicles

sacs made of membrane

Glycoproteins

proteins that have carbohydrates covalently bonded to them

Transport Vesicles

vesicles in transit from one part of the cell to another

Phagocytosis

the process of engulfing smaller organisms or food particles

Food Vacuoles

vacuoles which store food

Contractile Vacuoles

they pump out excess water due to osmosis

Cristae

infoldings of the inner membrane in 

mitochondria

Mitochondrial Matrix

the space in between the cristae

Thylakoids

membranous system in the form of interconnected sacs in chloroplast

Granum/Grana

each stack in the choloroplast

Stroma

the fluid outside the thylakoids

Centrioles

composed of nine sets of triplet microtubules arranged in a ring

Integral Proteins

proteins which penetrate the hydrophobic core of the lipid bilayer

Peripheral Proteins

proteins that are not embedded in the lipid bilayer, but are loosely bound to the surface

Glycoproteins

carbohydrates covalently bonded to protein

Glycolipid

carbohydrates covalently bonded to lipid