Tags & Description
Membrane transport
substances must travel through the plasma membrane
Substances want
equilibrium
Plasma Membrane
phospholipid bilayer is differentially permeable
Passive Transport
movement of molecules without energy
diffusion
passive transport from an area of high concentration to low concentration
Facilitated Diffusion
transport proteins help move hydrophilic and charged particles across the membrane (High to Low)
Osmosis
diffusion of water across a membrane from high to low concentration (of the water)
How does water move if a cell is placed in saltwater (saltwater is saltier than the water in the cell)
Osmosis will cause water to move out of the cell
Osmosis
diffusion of water across a membrane from high to low concentration
Aquaphorins
special proteins that help water cross the membrane faster/easier
Does water require aquaphorins to cross the membrane?
NO
What describes the active transport of potassium?
K+ will move from low to high concentration, energy is used
Active transport
uses energy to take things from low to high concentration
Exocytosis
a membrane bound vesicle fuses with the membrane and expels the large molecule outside the cell
Endocytosis
a vesicle pinches the plasma membrane inward, and brings a large molecule into the cell
Nutrient
substance in food that provides structural materials or energy
Macronutrients
nutrients required in large amounts
Do humans get half our water from our food?
yes
How much percent water are humans?
78-43% water (declines with age)
Carbohydrates
main energy source, ex. bread, cereal, rice, pasta
Digestion of Carbohydrates
simple sugars: digested easy complex carbohydrates: digested slowly
Healthy diet
carbs should mostly be complex carbohydrates
Whole food
unprocessed food not stripped of nutrition
Processed food
processing, refining, grinding
Furver (roughage)
indigestible. complex carbohydrates, some digested by bacteria in large intesting
Proteins
parts of cellular structures and processes, ex beef, eggs, gluten
Protein structure
polymers of amino acids
Essential Amino Acids
cannot be made in the body, must get from food
Nonessential amino acids
made in body
Complete protein
contains ALL of the essential amino acids
A fatty acid tail contains carbon that is double bonded to another carbon, what fat has this structure?
Unsaturated fat
Fats
source of stored energy, ex. milk, cheese, insulates body and organs
Fat structural composition
3 carbon skeleton attacked to 3 fatty acid tails
Essential Body Acids
cannot be made in the body, ex omega 3
Saturated Fat
fatty acid carbon bond to as much hydrogen as possible, solid at room temp. ex. animal fats
Saturated Fats
fewer hydrogens are bound to carbons, liquid at room temp, ex. plant fats
Polyunsaturated fats
many double bonds
Hydrogenation
process adds hydrogen atoms to solidify unsaturated fats(ex. oils), ex margarine,
Trans Fat
produced by incomplete hydrogenation, double bonds are flat and not kinked, increased health risks
What vitamin can be synthesized by the human body?
Vitamin D
Micronutrients
required in small quantities, two types; vitamins and minerals, not broken down by the body
Vitamins
organic substances that mostly cannot be synthesized by the body
Fat Soluble
stored in fat, excess accumulation can be toxic
Minerals
inorganic substances (no carbon)
Minerals are:
water soluble, supplied through diet, essential, ex. calcium, magnesium
Calcium
commonly supplemented mineral, needed for blood clotting
Antioxidants
electron donor molecule, prevent cell damage
Metabolism
all chemical reactions occurring in the body
How do enzymes affect metabolic reaction?
Enzymes decrease the activation energy of a reaction
Enzymes
proteins that catalyze(speed up) chemical reactions, end in suffix -ase
Activation energy
energy required to start a metabolic reaction
Substrate
chemical being metabolized
Active site
enzyme region where substrate binds
Enzyme Specificity
each enzyme catalyzes a particular reaction bases on enzyme shape and active site shape
Metabolic Rate
measure of a person's energy use
basal metabolic rate
the energy use of a resting, wakeful animal, human is 1680 calories a day
What influences BMR?
exercise, bio sex, age, genetics
What part of this structure will be removed to release energy?
to the last negatively charged phosphate
Cellular Respiration
series of metabolic reactions converting food energy to a usable form and releasing waste products
Adenosine Triphosphate (ATP)
provides energy to drive processes in living cells
Phosphorylation
phosphate group transferred from ATP to ADP
What is the ADP and ATP battery analogy?
ADP: low battery ATP: full battery
Whats is the equation for cellular respiration?
glucose + oxygen = carbon dioxide + water, C6H12O6+6O2=6H2O+6CO2
Cellular respiration
requires oxygen from breathing; releases carbon dioxide for delivery to lungs for exhalation
Aerobic Respiration
occurs mostly in the mitochondria, series of complex directions
NAD+
taxicab for electrons
NAD+ is
empty, no electrons or hydrogen
NADH is
full of electrons and hydrogen
What are the three stages of cellular respiration?
Glycolysis
Citric acid cycle
Electron transport chain and ATP synthesis
What step of the cellular respiration does not require oxygen?
Glycolysis
Glycolysis
6 carbon molecules broken down into two pyruvic acid molecules, occurs in cytosol, doesn't need oxygen
After Glycolysis
pyruvic oxidation happens, 2 carbon fragment metabolized inside mitochondria
Citric Acid Cycle
series of enzyme catalyzed reactions in the mitochondrial matrix
What does the Citric Acid Cycle produce?
Produces 4ATP and 10 NADH
H+ and ATP synthase
26 ATP molecules synthesized, each NADH yields ~2.5 ATP
What is an inaccurate description of what happens in the electron transport chain and ATP synthesis?
Water molecules are dropped off by NADH and used by membrane proteins
If carbohydrates are unavailable
fats will be uses
If carbohydrates and fats are unavailable
protein will be uses
Why does lactic acid build up in muscle cells during intense exercise?
Oxygen is less available as an electron acceptor
Anerobic respiration
metabolic process to generate energy without oxygen
Fermentation
one process cells use to produce energy without oxygen