module 3 nitrition

why do all cells need energy?

for growth, repair, and movement

what is metabolism

the biochemical reactions within a living organism to maintain life

how is energy released from food?

by breaking the bonds in our food

what is ATP

ATP is the energy carrying molecule that supplies energy to cells

what is the analogy for ATP molecules

they are like “charged batteries” for cells

what is the relationship between food and ATP

cells break the chemical bonds in food to release energy, that released energy is then used to “charge” ADP back to ATP

what is ADP

ADP is the “drained battery” form of ATP

what are catabolic reactions

reactions that break down larger molecules in to smaller subunits and release energy

what are anabolic reactions

reactions that build larger molecules from smaller ones and require energy

how are catabolic and anabolic reactions related

they are coupled- catabolic reactions provide energy for anabolic reactions

what are enzymes

proteins that speed up chemical reactions; breaking down large food molecules into tiny soluble nutrients

what is metabolic rate

the amount of energy (calories) spent in a certain time

what is basal metabolic rate (BMR)

the number of calories burned to sustain life functions while fasting

what factors effect BMR

weight, height, sex, genetics, and hormones. the higher the BMR, the more calories you need/burn a day

what is RMR

the number of calories burned at rest, including digestion

what is digestion

• the breakdown of food into smaller subunits for absorption

• takes place in the digestive system or gastrointestinal tract

• long muscular tube witch provides room for digestion followed by selective absorption

what are the three main functions of the digestive system

digestion- large molecules from plants and animals are mechanically (chewing) or chemically (enzyme/acid) broken down to building blocks

absorption- those building blocks are taken up through the cells lining the GI tract entering blood or lymph

secretion- elimination of non-absorbed waste from the body

elimination- of microbes that enter food (supported by the immune system that protects GI cells from infection)

what is mechanical digestion

physical breakdown of food, like chewing and stomach contractions. peristalsis squeezes food as it moves through the GI tract

what is chemical digestion

the breakdown of food using enzymes, which speed up chemical reactions. major digestive enzymes are: amylase, lipase, peptidase, lactase, sucrase

what does amylase break down

starch (carbohydrates)

what does lipase break down

lipids (fats)

what enzymes break down protein

peptidase, protease, and pepsin

what does lactase break down

lactose (milk sugar) a carbohydrate

what does sucrase break down

sucrose (table sugar)

what are the major parts of the gastrointestinal (GI) tract

mouth, esophegus, stomach, small intestine, large intestine, rectum, anus

where are fats broken down

small intestine

what are the accessory organs of the GI tract

salivary glands, liver, gallbladder, and pancreas; for the chemical breakdown of food acid is needed, hydrochloric acid found in the stomach and enzymes that are made in the GI tract by organs above

function of salivary gland (accessory organ)

lubrication, amylase, and lipase

function of the liver (accessory organ)

secreting bile, and purifying blood from small intestine

function of gallbladder (accessory organ)

stores bile

function of pancreas (accessory organ)

produces digestive enzymes such as peptidase

how does food move through the GI tract

through peristalsis, which are waves of contractions

what regulates food movement through the GI tract

sphincters- muscular rings that prevent backflow or early release

what is a bolus

a mass of food mixed with saliva that moves from the mouth to the stomach

whats a chyme

a watery mixture of partially digested food and secretions (kidney/pancreas)oving through the intestines

what are feces

undigested fiber, bacteria, and old intestinal cells formed in the large intestine & excreted

what are the functions of the mouth in digestion

• taste analysis

• mechanical digestion (chewing, swallowing, lubrication by saliva)

• limited chemical digestion

what enzymes are found in saliva

salivary amylase (digests starch)

salivary lipase (digests fat)

esophagus

a tube from the pharynx (back of mouth) to stomach

what prevents food from entering the trachea (wind pipe)

eppiglotits

what is the function of the lower esophageal sphincher (LES)

it prevents back flow of acidic stomach contents in the esophagus

what are the main functions of the stomach

mechanical and chemical digestion, mucus protects the stomach from acid, protein breakdown by HCL, enzyme activation by HCL, pepsin protein digestion, mucus and HCL production stimulation, and vitamin B-12 absorption

what does hydrochloric acid (HCL) do in the stomach

it breaks down proteins and activates digestive enzymes

what does pepsin do in the stomach

it digests proteins

whats the function of bile in liver and where is it stored

bile emulsifies fat and is stored in the gallbladder

delivered to small intestine as needed

stores fat soluble nutrients

3 segments of small intestine

duodenum- food + pancreatic juice + bile

jejunum- absorbs nutrients and water

ileim- absorbs remaning nutrients and water

what molecules are absorbed in the small intestine

glucose, amino acids, fats, vitamins, most minerals, water 70% -90% of total, alcohol 80% of total, and bile acids

what digestive enzymes do pancreas produce

pancreas produce hormones and enzymes

proteas (protein digestion)(trypsin)

pancreatic amylase (starch digestion)

pancreatic lipase (fat digestion)

nucleases(nucleic acid digestion)

whats the main function of the large intestine (colon)

water and mineral absorption, vitamin absorption, and feces compaction

whatever not absorbed will be excreted (water, undigested fiber, bacteria). rectum collects and holds feces and anus

what are common symptoms of GERD, and what causes it

stomach acid or bile flows into food pipe and irritates the

lining

SNS- burning chest pain after eating, worsened when lying down

CAUSE- obesity, high fat diet, laying down after eating, meds (NSAIDs)

TREAT- lifestyle change, antacid, meds that reduce acid product, surgery

what are peptic ulcers, and what causes them

stomach lining erosion due to helicobackter pylori infection or NSAIDs in the esophagus or duodenum (pain, bleeding, perforation)

SNS- stomach pain 2 hrs after eating, weight loss lack of appetite, nausea and vomiting.

TREAT- antibiotics, antacids, meds that reduce acid product

symptoms of peptic ulcers

stomach pain, weight loss, nausea, vomiting

what causes diarrhea

infections, malabsorption (lactose intolerance), excessive fiber intake

what are key treatments for diarrhea

prevent dehydration with fluids and electrolytes, decrease; fat, fiber, poorly absorbed carbohydrates. seek medical help if; diarrhea is nore than 7 days, dehydration, blood in stool

what are common causes of constipation

low fiber diet, ignoring the urge to defeceate, muscle or nerve issues, and certain supliments (iron, calcium)

TREAT- increase fluid, fiber, physical activity, and regular bowel habits

what is diverticulosis

the formation of balloon-like structures (diverticuli) in the intestine. can be fatal

what is diverticulitis and what foods can worsen it

inflammation of diverticuli due to trapped food, worsened by corn and nuts

treatment for diverticulitis

fiber helps speed the movement and doesn’t allow food to get stuck, antibiotics help too

what is celiac disease

an immune response to gluten that damages the small intestine

flettens villi of small intestine, nutrient malabsorption

what foods contain gluten

wheat, barley, and rye

what are the symptoms of celiac disease

diarrhea, bloating, fatigue, weight loss, anemia

whats the only treatment for celiac disease

a strict gluten free diet