BIO 305 Nutrition in Humans Exam With Accurate
Solutions 100% Verified
nutrition
process by which organisms obtain food and energy for growth, repair and maintenance
of the body
what does nutrition comprise?
1. ingestion - intake of food into body
2. digestion - process where large food molecules are broken down into smaller,
simpler, diffusible molecules that can be absorbed into body cells
3. absorption - the uptake of substances into cells of body
4. assimilation - use of absorbed substances by cells to become part of body / new
cytoplasm / provide energy
5. egestion - discharge/expulsion of undigested matter out of body
absorption vs assimilation
absorption: uptake of substances into cells of body
assimilation: use of absorbed substances by cells to become part of body / provide
energy
absorption: physical process that involves movement of substances across intestinal
wall into blood capillaries and lacteals
Assimilation: metabolic process involving chemical reactions by which ingested
materials are transformed into forms that can be utilized by body cells
absorption takes place in the small intestine and assimilation takes place in all the cells
in different parts of the body
absorption requires digestive enzymes while assimilation doesn't require digestive
enzymes
types of nutrition
,1. Autotrophic
2. Heterotrophic
Autotrophic nutrition
The manufacture of food out of a light source (photosynthesis) e.g. most plants
Heterotrophic nutrition
Acquisition of food from the environment, e.g. animals
What does food consist of?
Complex organic compounds: Carbohydrates, fats, proteins
- large molecules cannot be absorbed by various body parts
- digestion occurs to break down food into smaller, soluble molecules to be absorbed
what type of process is digestion?
catabolic: complex molecules are broken into simpler molecules
why is digestion important?
needed to break large insoluble food materials into smaller, DIFFUSIBLE, simpler and
soluble molecules that can be ABSORBED into blood stream and transported to body
cells to be UTILISED
physical digestion
- describe where and how
- mechanical break up of food into SMALLER pieces > increase SA to volume ratio for
digestive enzymes to act on food efficiently
- occurs in mouth, stomach, small intestine:
MOUTH - chewing food by action of teeth & tongue
, STOMACH - PERISTALSIS, continual contractions & relaxations of stomach muscles
churn food into smaller pieces + mix w digestive enzymes
SMALL INTESTINE - bile salts emulsify fats into droplets that are smaller
chemical digestion
- ENZYMATIC REACTIONS that break food from large to small, DIFFUSIBLE molecules
that can be taken up by body cells
- accomplished by digestive enzymes in mouth, stomach, small intestine
where does chemical digestion occur and what is digested?
buccal cavity/mouth: STARCH digestion
stomach: PROTEIN digestion
small intestine: carbohydrate, protein and FAT digestion
enzymatic reactions in digestion
- enzymes, substrates, end products
- lipases: fat digesting enzyme -> digest fats (substrate) into glycerol & fatty acids (end
products)
- proteases: protein digesting enzyme -> digest protein (substrate) into short peptides,
then amino acids (end products)
- amylase: starch-digesting enzyme -> digest starch (substrate) into maltose (end
products)
human alimentary canal
digestive tube that extends from the mouth to the anus
why is the length of the digestive system so long?
to INCREASE SURFACE AREA to digest food -> helps digestion by allowing more time
Solutions 100% Verified
nutrition
process by which organisms obtain food and energy for growth, repair and maintenance
of the body
what does nutrition comprise?
1. ingestion - intake of food into body
2. digestion - process where large food molecules are broken down into smaller,
simpler, diffusible molecules that can be absorbed into body cells
3. absorption - the uptake of substances into cells of body
4. assimilation - use of absorbed substances by cells to become part of body / new
cytoplasm / provide energy
5. egestion - discharge/expulsion of undigested matter out of body
absorption vs assimilation
absorption: uptake of substances into cells of body
assimilation: use of absorbed substances by cells to become part of body / provide
energy
absorption: physical process that involves movement of substances across intestinal
wall into blood capillaries and lacteals
Assimilation: metabolic process involving chemical reactions by which ingested
materials are transformed into forms that can be utilized by body cells
absorption takes place in the small intestine and assimilation takes place in all the cells
in different parts of the body
absorption requires digestive enzymes while assimilation doesn't require digestive
enzymes
types of nutrition
,1. Autotrophic
2. Heterotrophic
Autotrophic nutrition
The manufacture of food out of a light source (photosynthesis) e.g. most plants
Heterotrophic nutrition
Acquisition of food from the environment, e.g. animals
What does food consist of?
Complex organic compounds: Carbohydrates, fats, proteins
- large molecules cannot be absorbed by various body parts
- digestion occurs to break down food into smaller, soluble molecules to be absorbed
what type of process is digestion?
catabolic: complex molecules are broken into simpler molecules
why is digestion important?
needed to break large insoluble food materials into smaller, DIFFUSIBLE, simpler and
soluble molecules that can be ABSORBED into blood stream and transported to body
cells to be UTILISED
physical digestion
- describe where and how
- mechanical break up of food into SMALLER pieces > increase SA to volume ratio for
digestive enzymes to act on food efficiently
- occurs in mouth, stomach, small intestine:
MOUTH - chewing food by action of teeth & tongue
, STOMACH - PERISTALSIS, continual contractions & relaxations of stomach muscles
churn food into smaller pieces + mix w digestive enzymes
SMALL INTESTINE - bile salts emulsify fats into droplets that are smaller
chemical digestion
- ENZYMATIC REACTIONS that break food from large to small, DIFFUSIBLE molecules
that can be taken up by body cells
- accomplished by digestive enzymes in mouth, stomach, small intestine
where does chemical digestion occur and what is digested?
buccal cavity/mouth: STARCH digestion
stomach: PROTEIN digestion
small intestine: carbohydrate, protein and FAT digestion
enzymatic reactions in digestion
- enzymes, substrates, end products
- lipases: fat digesting enzyme -> digest fats (substrate) into glycerol & fatty acids (end
products)
- proteases: protein digesting enzyme -> digest protein (substrate) into short peptides,
then amino acids (end products)
- amylase: starch-digesting enzyme -> digest starch (substrate) into maltose (end
products)
human alimentary canal
digestive tube that extends from the mouth to the anus
why is the length of the digestive system so long?
to INCREASE SURFACE AREA to digest food -> helps digestion by allowing more time
