BIO EXAM: Lecture 4

What are the 3 types of fiber?

Microfilaments(actin filaments), microtubules, intermediate filaments

Microfilaments(actin filaments)

Two protein chains loosely twined together(Change more frequently)

Microtubules

-Largest of cytoskeletal elements(13 filaments)

-alpha and beta tubulin subunits

Intermediate filaments

-Between the size of actin filaments + microtubules

-Very stable

What is this?

Microtubules

What is this?

Microfilament

What is this?

Intermediate

Villi

-Non-motile

-Small intestine mucosa

-Connective tissue + vessels

-Surface area for absorption

Microvilli

-Non-motile

-Intestinal epithelial cells

-Actin filaments

-Further absorptive surface

Cilia

-Motile

-Trachea epithelium

-Microtubules(9+2 axoneme)

-Sweep mucus & debris upward(mucociliary escalator)

Flagellum

-Motile

-Human sperm tail

-Microtubules(9+2 axoneme)

-Propel entire cell forward

Plant Cell Walls

-Polysacharide

-Beta-glucose

-Cellulose

Extracellular Matrix (ECM)

-Secrete glycoproteins into the space around them

-Collagen may be abundant

What is this is?

Extracellular Matrix Structure

Types of Animal Cell Junctions

Tight junction, adhesive junction (desmosome), communicating junction

What animal junction is this?

Tight

What animal junction is this?

Adhesive

What animal junction is this?

Communicating

What cells have plasmodesmata?

Plant cells

Plasmodesmata

-Specialized opening in their cell walls

-Cytoplasms of adjoining cells are connected

What function is the plasmodesmata similar to?

Gap junctions in animal cells

Nucleus

Stores DNA
(instructions) and directs
activities

Nuclear Pores /
Nuclear Basket

Control what enters/exits the nucleus

Ribosomes

Build proteins

Rough ER

Synthesizes proteins, folds them, initial modification

Smooth ER

Synthesizes lipids, detoxifies drugs, stores calcium

Golgi apparatus

Modifies, sorts, packages proteins/lipids

Transport Vesicles

Move materials between organelles

Lysosomes

Digest and recycle macromolecules & old organelles

Peroxisomes

Break down fatty acids & detoxify harmful substances (using hydrogen peroxide +
catalase)

Mitochondria

Produce ATP through cellular respiration

Chloroplasts

Perform photosynthesis, make glucose

Vacuole

Storage of water, nutrients, toxins; plant central vacuole maintains turgor pressure

Cytoskeleton

Provides shape, transport, movement

Plasma membrane

Selective barrier for entry/exit

Extra cellular matrix

Support, signaling outside cell

Centrosome

Organizes microtubules, cell division

This is an image showing?

Fluid Mosaic Model of Cell Membranes

What structure is this?

Phospholipid

What structure is this?

Sphingolipid (Sphingomyelin)-Long-chain Amino Alcohol (Sphingoid base)

What is stable?

Phospholipid bilayers→
Its polar head toward water and its nonpolar tail away.

Are bilayers fluid or rigid?

fluid

Hydrogen bonding of water to itself is what?

Cohesion

Hydrogen bonding to polar heads is what?

Adhesion

Is this a solid or liquid form?

Solid

Is this a solid or liquid form?

Liquid

Saturated fatty acids make the membrane more or less fluid than unsaturated fatty acids

Less fluid!

Warm temperatures make the membrane more or less fluid than cold temperatures

More fluid!

In colder weather what is introduced by the enzyme to make the
membrane more fluid?

Double bonds

ER Membrane

Plasma membrane

Bubble

Micelle

Layer of a bubble

Transporter

Enzyme

Cell-surface receptors

cell-surface identity marker

cell to cell adhesion

attachment to the cytoskeleton