Human Systems Flashcards
what is the definition of METABOLISM?
all chemical reactions in a cell
what is the definition of CATABOLISM?
the break down of complex chemical structures to simpler molecules (an example of metabolism)
what is the definition of ANABOLISM?
combining simple molecules into complex structures (an example of metabolism)
what is a MACRONUTRIENT?
- any nutrient required in large amounts
- generally used as a source of energy (ex. macromolecules –> carbs, lipids, proteins, nucleic acids)
what is a MICRONUTRIENT?
- any nutrient required in small amounts
- can’t be used for energy
- essential
- play a unique role in the body (ex. micromolecules —-> vitamins + minerals
what are the two classes of nutrients?
- non-essential
2. essential
what is a non-essential nutrient?
necessary, but can be made by the body if lacking in diet
what is an essential nutrient?
must come from an external source (the body can’t make it)
what are MACROMOLECULES?
- large, complex organic molecules
- they are too large to be absorbed, the body must use hydrolysis to break them down and dehydration synthesis to rebuild them
- these include carbs, lipids, proteins and nucleic acids
what is DEHYDRATION SYNTHESIS?
- assembling of macromolecules from smaller units
- OH removed from one molecule and H removed from another —> empty space joins together
- gets help from enzymes
what is HYDROLYSIS?
- breaking down of a macromolecule into smaller subunits
- water is needed/added
- gets help from enzymes
what is an ENZYME?
a biological catalyst
what is the main role of a carbohydrate?
to provide the body with energy
what are carbs composed of?
C, H + O
what are the three main types of carbs?
- monosaccharides
- disaccharides
- polysaccharides
what is a MONOMER?
general term for the smallest repeating unit
what is an ISOMER?
same chemical formula, but different arrangements
what is a MONOSACCHARIDE?
- simple sugar
- most common: glucose, fructose, galactose
what is a DISACCHARIDE?
- formed when 2 monosaccharides are chemically bonded together through a dehydration reaction
- a glycosidic bond is formed between each monosaccharide
- broken by addition of water
what is a POLYSACCHARIDE?
- more than 3 monosaccharides bonded together
what is a STARCH?
- starch is linear unbranched chains of glucose units
- insoluble in water
what is GLYCOGEN?
- highly branched chains of glucose units
- broken back down into glucose when energy is needed
what are the roles of fats/lipids
they provide the body with energy, build cell membranes, insulation and protection
what are fats/lipids composed of?
C,H + O (makes them similar to carbs)
are fats/lipids soluble?
no
why do you get more energy out of fats than other macromolecules?
because they are high energy molecules, but the body does not choose fats to get energy from
what two component cells are lipids digested into?
- glycerol
2. fatty acid
what are the three types of lipids?
- Triglycerides
- Phospholipids
- Steroids
what are triglycerides used for?
used for storing energy
what do phospholipids make up?
they make up cell membranes
what do steroids form?
sex hormones (testosterone, estrogen)
what are the two types of fatty acid chains?
- unsaturated
2. saturated
what is an unsaturated fatty acid?
- at least one double bonded carbon atom
- liquid at room temperature
what is a saturated fatty acid?
- all of its carbon atoms joined by single bonds
- solid at room temperature
what are the roles of proteins?
- to build and repair cells
- the “doing” molecules in a cell
- make up most cellular structures
- 80% of the body’s structure is protein
- built by ribosomes
what do proteins act as?
- enzymes
- antibodies
- hormones
- energy source
- transport molecules
- structural components of cells
what are amino acids?
the monomer of a protein
what are amino acids made of?
C, H, O + N
how many different amino acids exist?
20
what causes amino acids to vary?
their “R Group”
how many amino acids can our bodies make?
our bodies can make 11/20 amino acids, the other nine come from our diets
what are chains of amino acids called?
polypeptides
what is the name of the bond that joins one amino acid to another?
peptide bond
how many amino acids make up a polypeptide?
3-300
can the body store amino acids?
no
where are excess amino acids rearranged?
the liver
what are the 4 protein structures?
- Primary Structure
- Secondary Structure
- Tertiary Structure
- Quaternary Structure
what is the primary structure of a protein?
- a long wavy chain of amino acids
what are the two secondary structures of proteins?
- alpha helix (spiral/coil) - stretches
2. beta pleated (zigzag) - does not stretch
what is tertiary structure?
- different types of structures together
what is quaternary structure?
more than one protein bonded to another
what can alter a protein’s shape?
- heat
- radiation
- bacteria
- illness
- pH
what process breaks down proteins?
hydrolysis
where are proteins first digested?
the stomach
what does the iodine test test for?
tests for starch
what does Benedict’s test test for?
tests for reducing sugar
what does the brown paper test test for?
tests for lipids
what does the biuret test test for?
tests for proteins
what is the main role of nucleic acids?
to direct the growth and development of all organisms
what are the 3 nucleotides?
- sugar
- phosphate
- nitrogen ring
what are micromolecules?
- not used as an energy source
- only need small amounts
- vitamins/minerals
what is the main role of vitamins?
- they help enzymes function
- called “coenzymes”
what are water soluble vitamins?
they must dissolve in water for absorbtion
what are fat soluble vitamins?
they will only be absorbed if there is fat in the intestine (should be taken with meals)
what vitamins can be stored in the body?
A and D
which vitamins can the body produce?
D, K and B
what are the main roles of minerals?
- assist in body functions
- make up essential components of hormones and enzymes
- called “cofactors”
