UConn Biology 1107 Chapter 6

Cell Theory

all organisms are made of cells and all cells come from pre-existing cells

form fits function

cell fractionation

takes cells apart and separates the major organelles from one another in the act of "blending"

microscopy

scientists use microscopes to visualize cells unbeknownst to the naked eye

magnification

the ratio of an object's image size to its real size

resolution

the measure of the clarity of the image

contrast

visible differences in parts of the sample

scanning electron

provides images that look 3D

transmission electron

used to study the internal structure of cells

electron microscope

used to study subcellular structures

nuclear envelope

encloses the nucleus and separates it from the cytoplasm

plasma membrane

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

eukaryotic cell

- DNA in a nucleus

- membrane bound organelles

- protists, fungi, animals, and plants

prokaryotic cell

- DNA in a nucleoid

- no nucleus

- no membrane-bound organelles

- domains Bacteria and Archaea

all cells have-

- DNA

- ribosomes

- cytoplasm

- plasma membrane

pores

regulate entry and exit of molecules from the nucleus

nuclear lamina

maintains nucleus' shape

nucleolus

site of ribosomal RNA synthesis

smooth ER

- lacks ribosomes

- synthesizes lipids

- metabolizes carbs

- detoxifies poison

- stores calcium

rough ER

- ribosomes studding surface

- bound ribosomes which secrete glycoproteins

- distributes transport vesicles

- membrane factory

glycoprotein

proteins covalently bonded to carbs

transport vesicles

proteins surrounded by membranes

chromatin

- DNA & proteins in the nucleus

- condenses to form discrete chromosomes

ribosomes

- "protein factories"

free ribsomes

in the cytosol

bound ribosomes

outside of the endoplasmic reticulum OR the nuclear envelope

Golgi apparatus

- modifies products of ER

- manufactures certain macromolecules

- sorts and packages materials into transport vesicles

lysosome

an organelle containing digestive enzymes

autophagy

lysosomes use enzymes to recycle organelles and macromolecules

mitochondria

site of aerobic cellular respiration, which generates ATP

membranes of the mitochondria

- smooth outer membrane

- inner membrane is folded into cristae, and has both intermembrane space and mitochondrial matrix

mitochondrial matrix

metabolic steps of cellular respiration

chloroplasts

- sites of photosynthesis

- contains chlorophyll

thylakoids

membranous sacs that are stacked to form a granum (grana plural)

stroma

the internal fluid of chloroplasts

cytoskeleton

a network of fibers extending throughout the cytoplasm that organizes the cell's structures and activities throughout the cytoplasm

microtubules

- thickest of the vesicles

- guides organelle movement

- separates cell chromosomes during cell division

microfilaments

- thinnest of the vesicles

- bears tension

- cortex supports shape

intermediate filaments

- a vesicle of the cytoskeleton

- supports cell shape and fixes organelles in place

cilia and flagella's common ultrastructure

- plasma membrane covered microtubules

- basal body that helps to anchor

- dynein

dynein

motor protein that drives bending movements for cilium/flagellum, and moves it by "walking"

How do cilia and flagella differ?

In their beating patterns controlled by their microtubules.