IB SEHS Topic 3 (FULL)
nucleus
A part of the cell containing DNA and RNA and responsible for growth and reproduction
briefly explain the process of metabolism
all biochemical processes that occur with any living organism to maintain life
Function of carbohydrates
Act as metabolic fuels and energy stores - especially during intense and prolonged periods of exercise
What is the origin of saturated fats?
Animal sources: meat, poultry, full-fat dairy, tropical oils (palm and coconut)
One way dietary guidelines for athletes vary from non-athletes
Athletes require more fluids and energy from macronutrients
Ratio of elements in a carbohydrate
C = 1, H = 2, O = 1
Examples of minerals or trace elements needed by the human body
Ca, Cl, Mg, Na, K, P, Cu, Cr, Fe, I, F, Zn, Se, Mn, Mb
State the chemical composition of a glucose molecule
Carbon, hydrogen, and oxygen (C6H12O6)
State the approximate energy content per 100 g of carbohydrate, lipid, and protein
Carbs: 1760 kJ Lipids: 4000 kJ Protein:1720 kJ
Describe the current recommendations for a healthy balanced diet
Carbs: 50% of diet Fiber: 25-30 grams (6-8 soluble) Water: 64 oz daily Protein: depends on age, gender, and daily activity, anywhere from 80-100 g Fats: 20-30% of our total calorie intake Salt: less than 2,300 mg a day
Explain how glucose molecules can combine to form disaccharides
Condensation reactions remove a water molecule to combine the glucose molecules
State the chemical composition of a protein molecule
Consists of carbon, hydrogen, oxygen, and nitrogen
how does adenosine lose and gain a phosphate molecule
Energy from catabolism attaches a phosphate to ADP forming ATP. Loss of a phosphate from ATP occurs when phosphorylation breaks the bond which provides energy for cellular work.
Function of proteins
Energy source, (1) structural (muscles, bones, skin, cells) types, (2) transport/communication types (neurotransmitters, etc.), (3) protective types (antibodies, mucus), and (4) enzymatic types (digestion, gas transport)
Distinguish between an essential and a non-essential amino acid
Essential: can't be synthesized from the human body, must be obtained from diet non-essential: can be synthesized by the human body
List the macronutrients
Fat(lipid), carbohydrate, protein, and water
Needed to prevent colorectal cancer
Fiber
what occurs in lipolysis
Glucagon and adrenaline are secreted which acts opposite of insulin (lipids are split into fatty acids...)
what occurs in glycogenolysis
Glucagon is secreted by alpha cells from the pancreas and acts opposite of insulin. Adrenaline is also stimulated and reacts like glucagon. Both cause glycogen to be split into glucose molecules.
contribution of the three energy systems during exercise
all three work together but one is always dominant (depended on intensity and duration of exercise)
briefly explain the process of anabolism
building up of simpler molecules into larger molecules, requires an input of energy
Needed for bone density and teeth
calcium (Ca)
An excess amount of this in the diet could cause onset of diabetes
carbohydrates
briefly explain the processes of aerobic catabolism and anaerobic catabolism
catabolism = breaking down complex organic compounds into simpler ones - energy releasing {aerobic = with oxygen, anaerobic = without oxygen}
lysosomes
cell organelle filled with enzymes needed to break down certain materials in the cell
cell respiration
controlled release of energy in the form of ATP from organic compounds
how does ATP-CP resynthesize ATP
creatine phosphate (CP), is broken down to provide a phosphate molecule for re-synthesis of ATP that has been utilized during the initial stages of exercise
first energy source used when muscles contract
creatine phosphate stores
which energy system is mainly used by sprinters
creatine phosphate system (anaerobic) is mainly used, unless the sprint takes longer than 20 seconds
which energy system is mainly used by team sport athletes
depends on the stop/start action and sprints needed for the game; both anaerobic CP and the lactic acid system are used
oxygen deficit
difference between the amount of oxygen consumed during exercise and the amount which would have been consumed if aerobic respiration occurred immediately
oxygen debt
excessive post exercise oxygen consumption (EPOC), demand for oxygen is greater than supply and higher than that of typical resting state
aerobic system (fatty acids)
fats are broken down by beta oxidation that liberates a greater number of electrons, thus more ATP (oxygen required); protein can also be utilized
aerobic fatty acid beta oxidation system
fatty acid => acetyl CoA => Krebs => etc, 1 fatty acid = 14 ATP, slower acting, occurs in mitochondria, carbon dioxide/water are by-products
anaerobic respiration
forms 2 ATP, less energy and no oxygen
aerobic respiration
forms 38 ATP, more energy and requires oxygen
antagonist of insulin hormone
glucagon
energy source used secondly when muscles exercise
glucose
molecule that serves as the major source of readily available fuel for neurons and blood cells
glucose
aerobic glucose oxidation system
glucose => pyruvate => Krebs => etc., 1 glucose = 36 ATP, slower acting, carbon dioxide/water are by products
how do fasting and exercise affect the body's glucose levels
glucose is removed from the blood which stimulates release of glucagon and adrenaline (causing glycogen, lipids and proteins to break down)
glucose forms glycogen
glycogenesis
what process forms glycogen
glycogenesis causes many glucose molecules to link together to form glycogen
what process converts glycogen into glucose
glycogenolysis breaks glycogen into glucose
breakdown of glucose into ATP
glycolysis
anaerobic lactic acid system
glycolysis uses glucose (1 glucose = 2 ATP), occurs quickly, begins when PCr fades (good for hard exercise); lactic acid and lower pH are by products
process that forms glucose from fats or proteins
glyconeogenesis
ETC (electron transport chain)
hydrogen splits into hydrogen ions and electrons, this produces 34 ATP
cristae of mitrochondria
infoldings of the inner membrane of a mitochondria that houses the electron transport chain and the enzyme catalyzing the synthesis of ATP
hormone that directs cells to absorb materials such as glucose or amino acids
insulin
Needed for hemoglobin function
iron (Fe)
what happens to blood glucose levels during exercise
muscle contraction and insulin both stimulate glucose to be taken into muscle cells from the blood (it decreases in the blood but increases in the muscle cells)
Storage location of glycogen
muscles (skeletal) and the liver
Needed for cell membrane production
phospholipids (fats)
mitochondria
powerhouse of the cell, organelle that is the site of ATP production
Which energy source is the least desirable type to be used as fuel?
proteins (muscle)
what happens to pyruvate if oxygen is present
pyruvate enters the mitochondria and is metabolized into carbon dioxide and water
what happens to pyruvate if oxygen is lacking
pyruvate is converted into lactate, transported back to the liver to reform glucose
ribosomes
sites of protein synthesis in cells
Golgi apparatus
stack of membranes in the cell that modifies, sorts, and packages proteins from the endoplasmic reticulum
what is glycogen and where is it generally stored
storage molecule of carbohydrates, stored in skeletal muscles and liver
what is glycolysis
the breakdown of glucose by enzymes, releasing energy (ATP) and pyruvic acid
where does glycolysis take place
the cytosol of cells
ATP-CP or creatine phosphate (PCr) system benefit
used for first 10 seconds (with the 2 seconds worth of ATP in the muscle), runs out quickly, ATP quickly regenerated but runs out fast
inner matrix of the mitochondria
viscous cytoplasm containing the mitochondria DNA, ribosomes, soluble enzymes, small organic molecules, nucleotide co-factors, and inorganic ions
lactic acid system (anaerobic glycolysis) is used
when PC is depleted the lactic acid system takes over; glucose is broken down into pyruvate without using oxygen. This system peaks at 15 seconds.
outer smooth membrane of the mitochondria
works with the inner membrane to regulate what enters and leaves the mitochondria
aerobic system (glucose)
Glycolysis occurs but pyruvic acid is by product, not lactic acid. This involves Krebs cycle; NO by products and more energy is created, by passing electrons through the transport chain. At 55 seconds, aerobic system is DOMINANT and takes over.
Function of fats (lipids)
Important source of energy in recovery periods, physically protects vital organs, controls body temperature, assists in hormone synthesis, cell membranes and transports fat-soluble vitamins
how does insulin affect glycogen formation
Insulin stimulates glycolysis, gluconeogenesis is inhibited, glycogenesis is promoted, lipolysis is inhibited and protein synthesis is promoted
Function of vitamins
Regulate energy release, co-factors in various chemical reactions
Distinguish between saturated and unsaturated fatty acids
Saturated: no double or triple bonds between carbons; unsaturated: 1 or more double or triple bonds in the fatty acid chain
rough endoplasmic reticulum
System of internal membranes within the cytoplasm. Membranes are rough due to the presence of ribosomes. functions in transport of substances such as proteins within the cytoplasm
explain the role of ATP in muscle contraction
actin and myosin in muscle fibers use ATP to provide chemical energy to drive the contraction process (only 2 seconds worth)
major sites of triglyceride storage
adipose tissue and skeletal muscles
which energy system is mainly used by endurance athletes
aerobic glucose/fatty acid systems - both the other two systems are used but not "mainly"
anaerobic creatine phosphate system
1 PCr = 1 ATP, occurs quickly, max use of 20 seconds exercise, creatine is another by-product
Function of minerals and trace elements
Involved in processes for maintaining bone and blood health, release of energy, muscle function, maintenance of cellular fluid balance
State the composition of triacylglycerol
Is an ester composed of a glycerol bound to three fatty acids
Macromolecule with the most energy per gram
Lipids (fats)
Function of water
Medium for biochemical reactions, transports nutrients/metabolites/waste/hormones/gases, thermoregulation, excretion, cell-cell and cell-environment communication, lubrication of joints and other surfaces
Explain how glucose molecules can combine to form polysaccharides
Multiple monosaccharides can be linked to a disaccharide to form a polysaccharide (condensation reactions)
What is the origin of unsaturated fats?
Plant-based foods: olive oil, olives, avocado, peanuts, cashew nuts, canola oil, seed, sunflower oil, rapeseed
List the micronutrients
Vitamins, minerals, trace elements
Composes the greatest percent of body mass
Water
Water molecule
What is removed when a monomer joins to a polymer through a dehydration reaction