Lecture 2 Flashcards
matter is made up of:
elements
Element:
a substance that cannot be broken down to other substances chemically
how many naturally occurring elements?
92
Compound-
a substance consisting of two or more
elements
how many of the 92 elements are essential to life?
About 20–25%
Atom’s chemical behaviour is determined by distribution of:
electrons in its electron shells
The periodic table of the elements shows the:
electron distribution
Valence electrons are:
those in outermost shell, or valence shell
Chemical behaviour of an atom is mostly determined by:
valence electrons
Elements with a full valence shell are
chemically inert
An example of ionic bond:
the transfer of an electron from sodium to chlorine
A compound that finds itself with an unpaired electron, becomes a
free radical.
Free radicals cause:
damage to your cells
antioxidants have:
extra electrons that they can donate to free radicals
The lesser component in a solution is the:
solute
Blood is a solution composed of:
plasma and cells
Plasma is ≈
92% water
Electrons that are shared between 2 atoms in a chemical
bond:
are not always shared equally
The oxygen atom is
very selfish.
in a water molecule, the electrons shared between hydrogen and oxygen spend more time orbiting the
oxygen atom
polar molecules:
partial negative charge around the oxygen atom and a partial positive charge around the hydrogen atoms.
The solubility of a compound:
how easily it dissolves, that is, forms a solution, in a liquid solvent.
is starch soluble in water?
partially
Acids are substances that:
lose H+ when dissolved in water
Bases are substances that:
remove and accept H+ when
dissolved in water.
Bases remove H+ from solutions by:
dropping OH-.
Bases accept H+ by
binding to H+.
Under normal conditions, the pH of your blood ranges from
7.35 to 7.45
With each whole number increase within the scale, the H+
concentration:
decreases 10 times.
Catabolic reactions involve:
breaking down molecules
Anabolic reactions involve
synthesizing new compounds.
example of catabolism:
during digestion
example of anabolism:
after sports injury
Metabolism refers to
the sum of all chemical reactions that occur in living cells.
__________are crucial for chemical reactions:
enzymes
Most enzymes end in:
“ase”
Tissues are:
a collection of cells.
The tissue that we care most about in this course is the:
epithelial tissue.
4 types of tissue:
epithelial
connective
muscle
neural
how many organs in body?
more than 40
how many organ systems in body?
11
collection of tissues that perform a
specific function:
organs
groups of organs that work together for similar purpose:
organ systems
Hollow tube from mouth to anus:
lumen
Transit time:
24 to 72 hours
Accessory organs:
gallbladder, pancreas, liver
The innermost lining of the digestive tract:
the mucosa
the physical and chemical breakdown of food into a form that allows nutrients to be absorbed:
digestion
the transfer of nutrients from the GI tract into the blood or lymph:
absorption
the process whereby solid waste is removed from the body:
elimination
Saliva from glands mixes with food and begins digestion of:
starch and fat
Saliva contains:
Enzymes that break down bacteria
– Mucus to lubricate and hold food together – Salivary amylase breaks down starch – Lipase breaks down some fat – And enhances perception of flavor
Umami means:
savory
the junction that opens to both the esophagus and the trachea:
the throat, or pharynx
The esophagus connects to:
the stomach
The trachea (windpipe) leads to
the lungs
what moves the bolus toward the stomach?
peristalsis
The trip from mouth to stomach takes:
less than 10 seconds
the first of several sphincters in the GI tract:
the gastroesophageal sphincter .
If food re-enters esophagus:
GERD
Mixed with stomach secretions food becomes
chyme
what prevent chyme from entering esophagus and regulate its entry into small intestine?
sphincters
what controls the rate that chyme is released into the small intestine?
Pyloric sphincter
The small intestine has 3 sections:
Duodenum (shortest segment 25cm) Jejunum Ileum (longest segment)
Most digestion and absorption occurs in the:
small intestine
The small intestine works as a team with the:
gallbladder, liver and pancreas.
what does Liver do?
Processes and stores nutrients, produces cholesterol, makes bile
what does the Gallbladder do?
Releases bile into the duodenum when fatty foods are present
what does the Pancreas do?
Secrets enzymes that break down carbohydrates, protein, and fat. Also neutralizes HCl in chyme when it enters the duodenum.
Beginning from the heart, the blood flows through:
Arteries Arterioles Capillaries: this is where gas + nutrient exchange between blood and cells occurs. Venules Veins
The Lymphatic System Circulates:
Fat- Soluble Nutrients
The Cardiovascular System Circulates:
Nutrients and Gases
Primary role of large intestine is
absorption of water and minerals, and dehydration of chyme before it is expelled
Functions of Large Intestine:
Housing of bacteria (microbiota)
