CELULA PROCARIOTA

Figure 4.5

Prokaryoticflagella

Nucleoid region (DNA)

RibosomesPlasmamembrane

Cell wall

Capsule

Pili

Fig. 4.1

Staining Differences

Gram Positive

Have a 2-layered, peptidoglycan-rich cell wall that easily absorbs a colored stain

Gram Negative

Have a 3-layered, peptidoglycan-poor cell wall that resists staining

Visión macroscópica del Muro de las estructuras tubulares del GI

LE 21-11b

Veinwith blooden route tothe liver

Musclelayers

Lumen

Largecircular folds

Villi

Nutrientabsorption

Lymphvessel

Intestinal wall

Villi

Bloodcapillaries

Epithelialcells

Nutrientabsorption

Lumen of intestine

Epithelial cells

Lymph

Blood

Fats

Aminoacidsand

sugars

Fattyacidsand

glycerol

Nutrient absorptioninto epithelial cells

Microvilli

LE 41-23

Key

Nutrientabsorption

Microvilli(brush border)

Epithelial cells

Lacteal

Lymphvessel

Villi

Largecircular

folds

Epithelialcells

Bloodcapillaries

Vein carrying bloodto hepatic portal

vessel

Muscle layers

Villi

Intestinal wall

Figure 21.10B

Musclelayers

Circular folds

Villi

INTESTINAL WALL

Blood vesselwith blooden route tothe liver

INTERIOR OF INTESTINE

Nutrientabsorption

Epithelialcells

Lumen

Bloodcapillaries

Lymphvessel

Nutrientabsorption

VILLI

Nutrientabsorption

Microvilli

EPITHELIALCELLS

Hepatic portal transports nutrients first to liver

The enormous microvillar surfaceIs an adaptation that greatly increases the rate of nutrient absorption

Epithelialcells

Key

Nutrientabsorption

Vein carrying blood to hepatic portal vessel

Villi

Largecircularfolds

Intestinal wallVilli

Epithelial cells

Lymph vessel

Bloodcapillaries

Lacteal

Microvilli(brush border)

Muscle layers

Figure 41.23

p.268

Disaccharidases

B. Funciones de las enzimas digestivasLos carbohidratos de digestión

Absorption of Proteins and Carbohydrates

Figure 14.13

p.306p.306Glucose Transport: a Na+-driven co-transporter

(facilitated diffusion)

(secondary active transport)

sugars exclusively absorbed as

monosaccharides

apical brush-border membrane

Silv. p.683

SGLT- sodium dependent glucose transporter.

Glut- facilitated diffusion transporter

Absorption of Fats

Figure 14.14

Fat dropletscoated with

bile salts

Fat globule

Bile salts

Micelles madeup of fatty acids,monoglycerides,

and bile salts

Epitheliumof small

intestine

Epitheliumof lacteal

Lacteal

p.308p.308

emulsification

micellar formation

hydrolysis

absorption

re-esterification

lipoprotein formation/transport

emulsification

micellar formation

hydrolysis

absorption

re-esterification

lipoprotein formation/transport

Fat Absorption: a problem of solvent association

Steps in the fat absorption process

Protein Digestion p.268

Silv. p.687Silv. p.687NaCl Absorption by the Colon

Small Intestine: Chemical Digestion