Lesson 2 - Food processing Flashcards
At the cellular level, what are used as a source of energy? (3)
1.carbohydrates
2.lipids
3.proteins
what are essential nutrients? why are they essential?
1.several amino acids
fatty acids
vitamins
minerals
2. must be supplied by the diet because 9/20 the body is unable to synthesize them
What is important to know about the table of amino acids? (2)
- the intake amounts of these amino acids change as a function of age (infants require more than adults).
- the essential amino acids don’t all require the same recommended intake amount
There are 2 types of fatty acids that we cannot synthesize. Which ones?
omega-3
omega-6
found on the phospholipids of the lipid bilayer
vitamines are synthesized by what?
plants (except vitamins B12 and D) when we eat plants, we incorporate these vitamins into our own tissues
There are 2 distinguised types of vitamines. Which are they?
water-soluble
lipid-soluble
What is Nicotinamide adein dinucleotide (NAD) in the citric acid cycle made of?
the vitamin niacin.
What is the vitamin Riboflavin a component of?
it is a component of the FAD molecule found in the citric acid cycle
without niacin or riboflavin what happens to our cells?
Our cells will generate no ATP
Minerals are the only essential nutrients that are…?
inorganic
Where do minerals come from?
Minerals are the products of the physical and chemical weathering of rocks.
Which minerals are essential to animals? (5)
- Calcium
- phosphorus
- potassium
- magnesium
- sodium
- iron
How do animals ingest minerals?
suspended in the soil solution, plants incorporate these minerals into their tissues. Once animals eat plants, the minerals are incorporated in their own tissues.
Minerals that function in fluid balance and nerve impulse transmission are called..?
electrolytes
which phylum has no digestive system?
prorifera (sponges)
How do sponges digest their food?
intracellularly- beating flagella move currents of water in from pores and out through the osculum- suspended within this water are food particles.
As the water flows through the collar of the choanocytes, food particles get attached and engulfed by phagocytosis. The food containing vacuole will fuse with lysosomes where hydrolytic enzymes break down the food particles. Alternatively, the food vacuoles can migrate towards the end of the choanocytes to get engulfed by amoebocytes. these amoebocytes cells have very active cytoskeletons allowing them to move around and deliver nutrients to the individual body cells of the sponge.
there is no cavity dedicated for food digesting food extracellularly
What do one-way digestive systems feature?
a single opening leading to a compartment called the gastrovascular cavity
What are the functions of the gastrovascular cavity?
- ingestion
- digestion
- absorption
4.elimination
how do cniderians like the hydra eat?
they use their tentacles to push the food into their gastrovascular cavity, then the epithelial cells found in the lining of the digestive tract release digestive enzymes that break down food particles and turn them into a liquid slurry that can be absorbed by the epithelial cells.
How do flatworms from the platyhelminthes phylym digest food?
muscle action pushes the digested food towards the terminal ends of the gastrovascular cavity.
The inflodings of the terminal ends creates a high surface area ensuring that every cell in the body is in direct contact with the gastrovascular cavity to receive nutrients. Gatrovascular cavity can also serve as the animals circulatory system.
which phylum have a two way digestive system?
Annelids and Birds
What specialized compatments do annelids and birds have?
- gizzard - composed of thick muscular tissue that helps to grind and pulverize food. + small stones that enhances the ability of the gizzard to pulverize the food
do small birds have a gizzard? what to they eat instead of seeds?
no.
it would compromise their ability to fly
instead they derive their nutrition from the fleshy parts of the injested fruits.
In mammals, where does food processsing begin? which tools enable this?
mechanical digestion begins in the oral cavity.
Teeth and the skeletal muscle tissue of the jaw are the tools that enable this.
Function of the tongue
a muscular organ that shapes food into a bolus and aids in swallowing. despite its musculature, the tongue is a very sensitive organ.
what enables the chemical digestion of food?
salivary glands associated with the oral cavity that secretes substances through a duct .
what is saliva made of? (5)
a mixture of salts, water and glycoproteins.
contains microbial agents to kill and disable pathogenic bacteria.
contains salivary amylase, a digestive enzyme that initiates the digestion of polysaccharides into smaller polysaccharides
What is the function of saliva?
to lubricate food and protect the lining of the mouth
what comes right after the salivary glands?
the pharynx
what does the trachea lead to?
the lungs
what does the esophagus lead to?
the stomach
what happens as the bolus is swallowed?
the epiglottis flips downwards, shutting off the access to the trachea and preventing us from chocking
what connects the oral cavity to the stomach?
the esophagus