Campbell Biology in Focus Chapter 4

light microscope

an optical instrument with lenses that refract (bend) visible light to magnify images of specimens

organelles

a membrane

electron microscope

microscope that forms an image by focusing beams of electrons onto a specimen

transmission electron microscope

an electron microscope used to study the internal structure of thin sections of cells

scanning electron microscope

an electron microscope used to study the fine details of cell surfaces

cell fractionation

takes cell apart and separates the major organelles from one another

prokaryotic cell

a type of cell lacking a nucleus and membrane

eukaryotic cell

a type of cell with a DNA membrane

cytoplasm

a jellylike fluid inside the cell in which the organelles are suspended

plasma membrane

is a selective barrier that allows sufficient passage of oxygen, nutrients and waste to service the volume of every cell and is the outer boundary of cell

nucleus

main control center of the cell contains dna

nuclear envelope

a double membrane that surrounds the nucleus in the cell

nuclear lamina

a net like array of protein filaments lining the inner surface of the nuclear envelope; it helps maintain the shape of the nucleus

chromosomes

dna structures that carry genetic information "colored bodies"

chromatin

dna and protein that makes up chromosomes

nucleolus

a specialized structure in the nucleus, formed from various chromosomes and active in the synthesis of ribosomes

ribosomes

a cell organelle composed of RNA and protein; the site of protein synthesis

endomembrane system

a "road system for the cell" in which most of the internal cell membranes are connected directly or indirectly includes nuclear envelope, endoplasmic reticulum, golgi, lysosomes, vacuoles, plasma membrane

vesicles

a sac made of membrane inside of cells

smooth er

is ER that does not have ribosomes attached it is a major site of lipid synthesis,

synthesizes lipids, involved in carbohydrate metabolism, detoxifies drugs and poisons

rough er

studded w/ ribosomes; sorts proteins and inserts them into the ER membrane

glycoproteins

a protein with one or more covalently attached carbohydrates (sugars)

transport vesicles

vesicles in transit from one part of the cell to another "bubble

golgi apparatus

another organelle made of stacked, flattened membranous sacs that plays an active role in processing products sent it from the er, especially proteins to be secreted from the cells

lysosome

a small, round cell structure containing chemicals that break down large food particles into smaller ones

phagocytosis

engulf food from outside cell, form food vacuole, fuse with lysosomes

vacuoles

membrane

food vacuoles

formed by phacogytosis; pinches off of the plasma membrane and encloses a food particle

central vacuole

a membranous sac in a mature plant cell with diverse roles in reproduction, growth, and development

mitochondria

the powerhouse of the cell a large organelle in eukaryotic cells that serves as the site of cellular respiration; uses oxygen to break down organic molecules and synthesize atp

chloroplasts

a structure in the cells of plants and some other organisms that captures energy from sunlight and uses it to produce food

endosymbiont theory

the theory that mitochondria and plastids, including chloroplasts, originated as prokaryotic cells engulfed by an ancestral eukaryotic cell the engulfed cell and its host cell then evolved into a single organism

cristae

an in folding of the inner membrane and the foldings increases the surface area for respiration to occur for enzymes that synthesizes atp

mitochondrial matrix

the compartment of the mitochondrion enclosed by the inner membrane and containing enzymes and substrates for the Krebs cycle

granum

a stack of thylakoids in a chloroplast

stroma

fluid inside chloroplasts that surrounds thylakoids

plastids

a group of membrane

peroxisome

an organelle that contains the enzyme catalase this enzyme deoxides harmful substances that enter the cell into unharmful substances

cytoskeleton

a network of long protein strands in the cytosol that organizes structures and activities in the cell

motor proteins

a protein that interacts with cytoskeletal elements and other cell components, producing movement of the whole cell or parts of the cell

centrosome

a structure present in the cytoplasm of animal cells that functions as a microtubule

centrioles

cylinder structures that are composed of 9 sets of triplet microtubules found in animal cell

flagella

long and whip

cilla

the hairlike projections on the outside of cells that move in a wavelike manner

basal body

a cellular organelle associated with the formation of cilia and flagella and similar to the centriole in structure

microfilaments

long, thin fibers made of molecules of actin that function in the movement and support of the cell

intermediate filaments

a component of the cytoskeleton that includes all filaments medium in range between microtubules and microfilaments

cell wall

a rigid structure found in plant cells that surrounds the cell membrane and provides support to the cell

primary cell wall

in plants, a relatively thin and flexible layer first secreted by a young cell

middle lamella

sticky layer between the cell walls of adjacent plant cells

secondary cell wall

a strong and durable matrix often deposited in several laminated layers for plant cell protection and support

thykaloid

a membranous sac stacked to form a granum

microtubules

thickest fibers made of molecules of actin that function in the movement and support of the cell