Campbell Biology Chapter 6

light microscopy

magnification of cellular structures up to 1000 X

scanning electron microscopy (SEM)

image of 3D surface coated with heavy metal like gold (100,000 X)

transmission electron microscopy (TEM)

image of ultra thin slice to view intracellular components (500,000 x)

cell fractionation

technique that breaks cells and separates their components

cytosol

aqueous part of cytoplasm within which particles and organelles are suspended

nucleoid

densly staining DNA region in a prokaryotic cell

chromatin

uncondensed DNA wrapped around histones (used during transcription)

chromosome

condensed chromatin (used during cell division)

nucleus

organelle that contains DNA and controls processes of cell

nucleolus

organelle where ribosomes are synthesized and partially assembled (within nucleus)

nuclear envelope

perforated double membrane that controls flow of materials (around nucleus)

nuclear lamina

netlike array of intermediate filaments that maintains shape of nucleus

ribosomes

organelles made of protein and rRNA that direct protein synthesis (in cytoplasm or tethered to rough ER)

free ribosomes

suspended in the cytosol and synthesize proteins that function in the cytosol

bound ribosomes

bound to a Rough ER and synthesize proteins that will function in the membrane or will be sent outside the cell

endoplasmic reticulum (ER)

internal membrane system in which components of cell membrane and some proteins are constructed

rough ER

organelle continuoues with nuclear membrane, to which ribosomes are tethered and proteins are synthesized for export

Glycoproteins

Membrane carbohydrates that are covalently bonded to proteins.

The Rough ER grows in place by...

After it grows, portions of the membrane are transferred to ______________ by...

adding membrane proteins and phospholipids to its own membrane.

other parts of the endomembrane system, transport vesicles

smooth ER

organelle where lipids are synthesized, detoxification occurs(in liver), and helps muscles contract

transport vesicles

A tiny membranous sac in a cell's cytoplasm carrying molecules from one place to another.

vesicles

small sacs surrounded by phospholipid bilayer that specialize in moving products into, out of, and within a cell

golgi apparatus

stack of membranes that modifies, sorts, and packages proteins for transport

cis vs trans side of the golgi apparatus

The cis side faces the ER and receives materials by fusing with transport vesicles. The trans side faces away from the ER and vesicles bud off from their that travel to other sites.

When molecules leave the golgi apparatus ___________ are added to help with sorting.

identification tags(phosphate groups or other groups)

lysosome

organelle filled with enzymes that break down macromolecules

phagocytosis

when extensions of cytoplasm surround and engulf LARGE food particles

Autophagy

A process in which lysosomes decompose damaged organelles to reuse their organic monomers

Food vacuoles are formed by ________ and fuse with ____________.

phagocytosis, lysosomes

contractile vacuole

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

central vacuole

membranous sac in plant cells with roles in reproduction, growth, and storage

Tonoplast

A membrane that encloses the central vacuole in a plant cell that is selective in its transport of solutes through the membrane

mitochondria

organelle in all eukaryotic cells where chemical energy in glucose and fats is transformed into ATP (cellular respiration SITE)

intermembrane space of mitochondria

space between inner and outer membranes

chloroplast

organelle in plants where sunlight energy is used to synthesize glucose (photosynthesis SITE)

endosymbiont theory

states that mitochondria and chloroplasts originated as prokaryotic cells engulfed by ancestral eukaryotic cell

mitochondrial matrix

(D) internal compartment of mitochondria (Krebs cycle SITE)

cristae

(E) inner membrane infoldinfgs of mitochondria that increase surface area (Electron Transport Chain and ATP synthase SITE)

Amyoplast

plastid that stores starch in roots

Chromoplast

a plastid that stores pigments for fruits and flowers

thylakoids

(C) flattened membrane sacs in chloroplast (Light Reactions SITE)

grana

(B) stacked thylakoid membranes in chloroplast

stroma

(A) innermost compartment of chloroplast (Calvin cycle SITE)

plastids

plant organelles surrounded by double membrane with their own DNA, that make and store food and pigments

peroxisomes

animal organelles that contain enzymes that detoxify alcohols, hydrogen peroxide, and other harmful chemicals

A by product of the reactions that the peroxisomes do is __________

hydrogen peroxide

cytoskeleton

microscopic network of protein fibers within cytoplasm that gives shape to cell

microtubule functions

(bottom) thickest, hollow tubes of tubulin proteins that make up cilia, flagella, and mitotic spindle

- organize the position of organelles

- direct intracellular transport

- also some movement(cilia and flagella)

microtubule structure

alpha tubulin and beta tubulin proteins organize into a hollow tube shape

dimer

a molecule or molecular complex consisting of two identical molecules linked together.

microfilaments

- control the outer shape of the cell(resist tension)

- (motility)muscle cell stretching and shrinking(movement like pseudopod arms)

- microvilli

microfilament structure

two intertwined strands of actin

pseudopodia

A cellular extension of cells used in moving and feeding that are controlled by microfilaments

intermediate filament function

- anchors organelles(keeps organelles in a stable position)

- provide mechanical strength

- forms nuclear lamina

intermediate filament structure

proteins coiled into cables

motor proteins

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

monorails

"Tracks" made by the cytoskeleton that vesicles can travel on

keratin

protein found in epidermis, hair, and nails

centrioles

organelles in animal cells from which mitotic spindle forms during cell division (resemble basal bodies)

mitotic spindle

microtubules that attach to centromeres through kinetochore proteins of chromosomes and pull sister chromatids apart during cell divisions

cilia

(A) short, many extensions of membrane-covered microtubules that move cell or materials past cell (ex. paramecium, trachea)

beating pattern like rowing

flagella

(E) long, few, whiplike tails of membrane-covered microtubules that move cells

beating pattern like snake

9+2 structure

cylinder of 9 microtubule doublets around a 1 doublet (make up cilia, flagella, mitotic spindle)

https://www.youtube.com/watch?v=sVHUO89-sXg

basal body

star of 9 microtubules triplets that anchors cilia and flagella in membrane (resembles centrioles)

Where is the basal body located?

LOCATED AT THE BOTTOM OF THE STRUCTURE INSIDE THE CELL AND IT ANCHORS THE CILIA/FLAGELLA

dyneins

proteins that connect microtubules in the 9+2 structure AND attach organelles to microtubules; when they contract, flagella/cilia move AND organelles "walk"

cytoplasmic streaming

circular flow of cytosol using myosin and actin filaments that speeds up distribution of materials within cells

What is the cell wall and what is its function?

a strong supporting layer of cellulose, chitin, or peptidoglycans around cell membrane in plants, fungi, or bacteria

function is to maintain cell shape, protect it, and prevent excess water uptake

middle lamina

(A) thin layer of adhesive extracellular material (pectins) between primary walls of adjacent young plant cells

primary cell wall

(B) thin, flexible and furthest out because it is secreted first

secondary cell wall

(C) strong, durable matrix added between plasma membrane and outermost structure for structure and support

extracellular matrix (ECM)

substance in which animal cells are embedded, consisting of proteins and polysaccharides

peptido/proteo-glycans

small core proteins with EXTENSIVE carbohydrate chains found in bacterial cell walls and animal ECM

glycoproteins

transmembrane proteins with SHORT carbohydrate chains that identify the cell

fibronectin

a glycoprotein that helps cells attach to extracellular matrix

integrins

transmembrane proteins that connect both to outside extracellular matrix and inside cytoskeleton of animal cells.

What is the purpose of fibronectin-integrin connections?

The link can help permit changes inside and outside the cell. It allows regulation of cell behavior.

plasmodesmata

(2) openings in plant cell walls through which strands of ER and cytosol connect adjacent cells

Plasmodesmata Function

Water and solutes can pass through. In some cases, RNA and proteins can also be exchanged.

tight junctions

(A) membrane fusions of neighboring cells that prevent leakage of fluid between them

desmosomes

(B) anchoring junctions that prevents cells subjected to mechanical stress from being pulled apart

gap junctions

(C) cytoplasmic channels between adjacent animal cells that allow movement of materials

microvilli

finger-like extensions of cells that increase surface area to increase absorption (ex. small intestine)

prokaryote

unicellular organism without nucleus and membrane bound organelles (archea and bacteria)

eukaryote

cells with nucleus and membrane bound organelles

collagen

fibrous protein found in connective tissues and ECM