Biology 6.1 Digestion Flashcards
Define Ingestion
Eating food
Define Digestion
The chemical breakdown of food into smaller molecules
Define Absorption
Passage of smaller molecules from the digestive system into the bloodstream or lymphatic system
Define Transport in reference to the digestive system
Delivery of small molecules to tissues by the circulatory system
When eating food, what 4 major macro molecules are ingested?
Nucleic Acids, proteins, lipids and carbohydrates
In digestion, explain how Nucleic acids are ingested and broken down
Nucleic acids are ingested as DNA and RNA and are broken down into nucleotides.
In digestion, explain how Proteins are ingested and broken down
Proteins are ingested as proteins and are broken down into amino acids.
In digestion, explain how lipids are ingested and broken down
Lipids are ingested as triglycerides and are broken down into glycerol and fatty acids.
In digestion, explain how carbohydrates are ingested and broken down
Carbohydrates are ingested as monosaccharides, disaccharides and polysaccharides and are broken down into monosaccharides.
What type of enzyme reactions occur in digestion
Catabolic: catabolic reactions are when larger complex molecules are broken down into their individual components. This process realizes energy
What can speed up an enzyme reaction?
Increasing temperature, however the human body cannot withstand high temperatures without destroying or causing damage to cellular structures
What is the digestive system also known as
Alimentary canal
Where does the digestive system begin and end
Begins with mouth ends with anus
What is peristalsis?
Muscular contraction that push food through the digestive tract
What enzymes does the pancreas produce?
Lipase, Amylase and Trypsin
What does lipase to in digestion?
Acts on lipids and hydrolyzes them into glycerol and fatty acids.
What does amylase do in digestion?
Acts on starch and hydrolyzes them into maltose (a disaccharide)
What does Trypsin do in digestion?
Acts on proteins and hydrolyzes a long polypeptide into shorter polypeptides.
What role does the pancreas have during digestion (pH)?
The pH of the stomach is very acidic siting at approximately a 2 on the pH scale. The enzymes that come from the pancreas require a pH of approximately 7. To remedy this the Pancreas secretes a
Aside from enzymes what else does the pancreas secrete?
Hormones
What is the role of the pyloric sphincter?
Its a valve in the stomach that opens and releases food from the stomach to the small intestine. It also secretes hormones that stop the production of gastric juices
What is the role of HCI (hydrochloric acid) in digestion?
Denatures proteins, causing them to unfold and be susceptible to digestive enzymes. It also activities enzyme pepsinogen which breaks proteins into smaller polypeptides. Kills pathogens in food such as bacteria
