Name: lipases and bile in fat breakdown
Uploaded: 2026-08-26T08:20:28.255Z
Duration: 1 min 16 s
Channel: JoVE

K12 Standards

Alabama Course of Study Science

9-12

Human Anatomy and Physiology

from-molecules-to-organisms-structures-and-processes

From Molecules to Organisms: Structures and Processes

9-12.HA.1.10

Lipid Digestion

- [Narrador] En la boca, la
digesti&#xF3;n de l&#xED;pidos comienza

cuando las gl&#xE1;ndulas de la
lengua liberan la lipasa lingual,

una enzima que inicia el proceso

de descomponer las grasas
grandes, como los triglic&#xE9;ridos,

el tipo de dieta m&#xE1;s abundante.

A medida que los l&#xED;pidos
viajan hacia el est&#xF3;mago,

se secretan enzimas
adicionales, lipasas g&#xE1;stricas.

Como los l&#xED;pidos son
hidr&#xF3;fobos, tienden a juntarse

en estos ambientes acuosos,
previniendo las lipasas

de romper las masas.

Una vez dentro del duodeno
del intestino delgado,

las sales biliares cubren las
gotas de grasa y causan la

dispersi&#xF3;n de los gl&#xF3;bulos,
creando una emulsi&#xF3;n, una

suspensi&#xF3;n acuosa.

Con mayor superficie disponible,

las lipasas pancre&#xE1;ticas
presentes pueden hidrolizar

los triglic&#xE9;ridos en
componentes m&#xE1;s peque&#xF1;os,

espec&#xED;ficamente &#xE1;cidos grasos
libres y monoglic&#xE9;ridos.

Ahora estos productos m&#xE1;s
peque&#xF1;os est&#xE1;n listos para ser

absorbidos por el intestino
delgado para m&#xE1;s procesamiento.

Wang, Tony Y., Min Liu, Piero Portincasa y David Q.-H. Wang. "Nuevos conocimientos sobre el mecanismo molecular de la absorción de ácidos grasos intestinales". Revista Europea de Investigación Clínica 43, n.º 11 (noviembre de 2013): 1203–23. [<a href="https://doi.org/10.1111/eci.12161" target="__blank">Fuente</a>]

digestión de lípidos

Los l&#xED;pidos son mol&#xE9;culas grandes que generalmente no son solubles en agua. Dado que la mayor&#xED;a de las enzimas digestivas del cuerpo humano est&#xE1;n basadas en agua, existen pasos espec&#xED;ficos que el cuerpo debe seguir para descomponer los l&#xED;pidos y ponerlos a disposici&#xF3;n para su uso. <h4>Lipasa lingual y lipasa g&#xE1;strica</h4> La lipasa lingual es una enzima secretada por las c&#xE9;lulas acinares de la gl&#xE1;ndula sublingual que ayuda a la digesti&#xF3;n de los l&#xED;pidos. Aunque se encuentra en la saliva, desempe&#xF1;a s&#xF3;lo un papel m&#xED;nimo en la descomposici&#xF3;n de los l&#xED;pidos en la boca. Curiosamente, la lipasa lingual tiene un pH &#xF3;ptimo de 3,5 a 6,0 y no se activa hasta que los alimentos masticados entran en el ambiente &#xE1;cido del est&#xF3;mago. La lipasa g&#xE1;strica es una lipasa &#xE1;cida secretada por las c&#xE9;lulas principales g&#xE1;stricas en el revestimiento del est&#xF3;mago. <h4>Lipasas &#xE1;cidas en humanos adultos y reci&#xE9;n nacidos</h4> La lipasa lingual y la lipasa g&#xE1;strica comprenden las dos lipasas &#xE1;cidas que se encuentran en el sistema digestivo humano. Estas lipasas son activas en el est&#xF3;mago pero r&#xE1;pidamente inactivadas por los &#xE1;cidos biliares en el duodeno. Juntas, la lipasa g&#xE1;strica y la lipasa lingual representan del 10 al 30% de la hidr&#xF3;lisis de l&#xED;pidos que ocurre en humanos adultos, siendo la lipasa g&#xE1;strica la que m&#xE1;s contribuye. Dadas las bajas concentraciones de lipasa pancre&#xE1;tica y sales biliares en la fase neonatal, las lipasas &#xE1;cidas son fundamentales para la digesti&#xF3;n de los l&#xED;pidos y representan el 50% de la hidr&#xF3;lisis de los l&#xED;pidos en los reci&#xE9;n nacidos. <h4>Bilis</h4> La bilis contiene sales biliares, lecitina y sustancias derivadas del colesterol, por lo que act&#xFA;a como emulsionante en el duodeno del intestino delgado. La emulsificaci&#xF3;n de las gotas de grasa en el duodeno aumenta su superficie m&#xE1;s de mil veces, haci&#xE9;ndolas m&#xE1;s accesibles a las lipasas pancre&#xE1;ticas.

Digestión de lípidos

Lipids are large molecules that are generally not water-soluble. Since most of the digestive enzymes in the human body are water-based, there are specific ...

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Education

Educación

JoVE Core

Biology

Biología

Genetics

Genética

Nutrition and Digestion

Nutrición y digestión

KEY TERMS AND CONCEPTS

TÉRMINOS Y CONCEPTOS CLAVE

lipases and bile in fat breakdown

Lipases and bile help the body break down lipids, which are large molecules that do not mix well with water. Because most digestive enzymes are water-based, lipids need special steps before the body can use them.

Lingual lipase is an enzyme made by acinar cells in the sublingual gland. It is found in saliva, but it has only a small role in the mouth. Its best pH, or acidity level, is 3.5-6.0, so it becomes active after chewed food reaches the acidic stomach.

Gastric lipase is another acidic lipase. It is secreted by the gastric chief cells in the stomach lining. Lingual lipase and gastric lipase are the two acidic lipases in the human digestive system, and they work in the stomach before bile acids in the duodenum quickly inactivate them.

In adults, these two lipases account for about 10-30% of lipid hydrolysis, or fat breakdown. Gastric lipase contributes the most. In neonates, however, acidic lipases are much more important. Because pancreatic lipase and bile salts are still low, they account for about 50% of lipid hydrolysis.

Bile contains bile salts, lecithin, and cholesterol-derived substances. In the duodenum, the first part of the small intestine, bile acts as an emulsifier. Emulsification breaks large fat droplets into smaller ones and increases their surface area more than a thousand-fold, which helps pancreatic lipases work more effectively.

Lipases and Bile in Fat Breakdown

overview of human digestion

Saliva, Stomach Acid, and Gut Health

The human digestive system is monogastric, which means the stomach has one chamber for digestion. Several other animals also have monogastric digestive systems, including pigs, horses, dogs, and birds. This chapter focuses on the human digestive system. Saliva is a watery fluid released by the salivary glands into the mouth. It is about 99.5% water and also contains electrolytes, mucus, white blood cells, epithelial cells, enzymes, and antimicrobial agents. The enzymes in saliva begin...

anatomy of the intestines

Small and Large Intestine Functions

The small and large intestines complete digestion and absorb nutrients, water, and electrolytes. They are two structurally distinct organs with different shapes and jobs. Together, they move food material from the stomach toward elimination. The small intestine is about 7 meters long and has an inner diameter of only 2.5 cm. Most nutrient absorption happens here, so its inner lining is highly folded and covered with villi, which are finger-like projections. Each villus contains hundreds of...

accessory organs

Digestive Glands and Enzymes

Digestive glands and accessory organs help break down food even though food does not pass through them. They add enzymes and other fluids to the digestive tract to support digestion. The salivary glands release saliva, a fluid that contains water, mucus, and amylase. Amylase is a digestive enzyme that starts breaking down starches and other carbohydrates before food reaches the stomach. The liver, gallbladder, and pancreas also support digestion. They send their secretions into the duodenum,...

carbohydrate digestion

Carbohydrate Breakdown in the Digestive Tract

Carbohydrate digestion breaks food carbohydrates into saccharides, or sugars, that the body can use for energy. It begins in the mouth during mastication, which means chewing. The masticated carbohydrates then pass through the stomach without being broken down further. Digestion starts again in the duodenum, the first part of the small intestine. There, pancreatic alpha-amylase and brush border enzymes on the microvilli help convert complex carbohydrates into monosaccharides. These simple...

protein digestion

Protein Breakdown and Amino Acid Use

Protein digestion starts in the stomach, where strong acid helps unfold protein structure and expose peptide bonds in polypeptide chains. Digestive enzymes then begin breaking those chains into smaller pieces that can be processed by the body. Pepsin is a protease, which means it is a protein-digesting enzyme. It is made in the stomach and works with chymotrypsin and trypsin, enzymes released in the small intestine. These enzymes cut specific links between amino acids and form shorter...

lipid digestion

Lipases and bile help the body break down lipids, which are large molecules that do not mix well with water. Because most digestive enzymes are water-based, lipids need special steps before the body can use them. Lingual lipase is an enzyme made by acinar cells in the sublingual gland. It is found in saliva, but it has only a small role in the mouth. Its best pH, or acidity level, is 3.5-6.0, so it becomes active after chewed food reaches the acidic stomach. Gastric lipase is another acidic...

neural regulation

Brain and Gut Control of Digestion

Brain and gut control digestion through a cephalic phase and the enteric nervous system. The cephalic phase begins when the brain sees or smells food. It sends impulses through cranial nerves to the salivary glands and stomach so the body is ready to eat. This first response is a conditioned, or learned, reaction to familiar foods. Appetite also changes the response. People may make more saliva and hear more stomach rumbling when they think about apple pie than broccoli. The hypothalamus and...

hormonal regulation

Digestive Hormones and Stomach Control

Digestive hormones control when the stomach makes acid and when food moves into the small intestine. They work with the neuroendocrine system, which links nerve signals and hormone release during digestion. In the stomach, proteins are detected by sensory neurons in the enteric nervous system. This stimulates the pyloric gland to release gastrin. Gastrin then helps trigger histamine release, and together they start hydrochloric acid production. The acid helps break food down into chyme. As the...

key terms and concepts

Learn how lingual lipase, gastric lipase, and bile help break down fats. See how emulsification in the duodenum increases surface area for digestion.

Lipases and Bile in Fat Breakdown | JoVE K12

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Next Generation Science Standards

High School

Life Science

HS-LS1-2

Florida Department of Education

SC.912.L.14

SC.912.L.14.46

new-york-state-science-learning-standards

New York State Science Learning Standards

Structure and Function

HS-LS1-2.

structural-organization-of-the-human-body-an-overview

Structural Organization of the Human Body: An Overview

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The Endoplasmic Reticulum

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1. Obtain, evaluate, and communicate information to explain how differences in cellular structure (mitochondria, cytoskeletal structure, endoplasmic reticulum, cell membrane) lead to differences in the function and organization of the four tissue types (epithelial, connective, muscular, and nervous).

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2. Obtain, evaluate, and communicate information to describe how the structures of the integumentary system and its accessory organs contribute to its function. Examples: how the layers of the skin contribute to homeostasis, the role of glands in thermoregulation and in hydration of skin and mucous membranes, the protective functions of hair and nails

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a. Construct an explanation of the relationships between the integumentary system and other organ systems, including the body's mechanisms for maintaining homeostasis. Examples: Explain how changes in vessel diameter and evaporation of water over the skin contribute to thermoregulation (cardiovascular). Explain how sweat is used to excrete nitrogenous waste from the blood (cardiovascular). Explain how the skin and mucous membranes create a barrier against infection (immune system).

9-12.HA.1.2.a

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Components ...

Classification of Bones

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Overview of the Axial Skeleton

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Introduction to Joints

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Joints

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3. Develop and use a model to illustrate how the structures of the skeletal system contribute to its function. Examples: Create a diagram or 3D model to illustrate bone shape, joint types, and bones in the appendicular and axial skeletons. Use models to illustrate the role of the skeletal system in movements around joints, support of a body structure, and protection of soft tissues.

9-12.HA.1.3

bone-formation-by-endochondral-ossification

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Bone Formation by Intramembranous Ossification

Intramembranous ossification is one of the two processes involved in the development of bones within an embryo. The flat bones of the face, most of the ...

Bone Remodeling and Repair

a. Obtain, evaluate, and communicate information describing the growth and development of the skeletal system.

9-12.HA.1.3.a

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Skeleton and Calcium Homeostasis

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The Bone Matrix

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b. Construct an explanation of the relationships between the skeletal system and other organ systems, including the body's mechanisms for maintaining homeostasis. Examples: Explain the role of spongy bone in hematopoiesis (cardiovascular system) and leukopoiesis (immune system). Explain how the storage of minerals in bone contributes to homeostasis.

9-12.HA.1.3.b

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Naming Skeletal Muscles

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4. Develop and build a three-dimensional model to illustrate the structures of the muscular system, including muscle locations, origins, and insertions, and explain their roles in movement and support. Example: Design and build a model of a lever to illustrate the relationship between bones and muscles and explain their roles in body movement and support.

9-12.HA.1.4

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excitation-contraction-coupling-in-skeletal-muscles

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Relaxation of Skeletal Muscles

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a. Model the cellular physiology of skeletal muscle, including how the cell functions in muscle contraction and relaxation. Example: Use straws and paper to create a model of a sarcomere to illustrate how the fibers move during contraction and relaxation.

9-12.HA.1.4.a

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b. Obtain, evaluate, and communicate information to explain muscle fatigue and tone in terms of muscle cell physiology.

9-12.HA.1.4.b

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5. Obtain, evaluate, and communicate information explaining the relationship between the structures and functions of the central nervous system and the peripheral nervous system.

9-12.HA.1.5

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9-12.HA.1.5.a

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b. Construct an explanation of the role of reflex arcs, the central nervous system, and special senses in the response to stimuli to maintain homeostasis and guide behavior. Example: smelling a strong odor initiating a sneeze response using a reflex arc; pupil diameter changing in relation to the amount of light entering the eye Clarification: Discussion of the anatomy and physiology of the sensory organs is not required.

9-12.HA.1.5.b

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c. Construct an explanation of the role of neurotransmitters in the functions and behavior of the nervous system. Clarification: Discussion of classes of neurotransmitters is not required.

9-12.HA.1.5.c

Lipases and Bile in Fat Breakdown

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