Topic A - introduction to human body and cell biology Flashcards
what is the configuration of carbohydrates
Cn H2n On
ratio ( 1:2:1 )
what are the 3 functions of carbohydrates? give on eg for each function and type of carbohydrate involved in function (PCS)
- primary energy source/fuel
( eg monosaccharide: glucose, fructose ) - cell structure such as cellulose in plant, chitin in animal
( eg disaccharides : maltose, sucrose )
* maltose : glucose + glucose. sucrose : glucose + fructose - stored energy in plants
( eg starch in potatoes, glycogen in animal )
polysaccharides
- cellulose
- chitin
- starch
- glycogen
what are monosaccharides?
as the simplest form of sugar, they cannot be further spilt or hydrolysed into smaller carbohydrates
usually colourless, water-soluble and crystalline solids
building blocks of more complex carbohydrates
eg glucose, ( simple sugar ) fructose ( in fruits )
what are disaccharides? give eg
two monosaccharides covalently linked
eg sucrose = glucose + fructose
maltose = glucose + glucose
( two glucose molecules )
what are oligosaccharides?
a few ( 3-20 ) monosaccharides covelently linked
what are polysaccharides? give eg
polymers ( 100s-1000s ) consisting of chains of monosaccharide or disaccharide units.
complex molecules with multiple monosaccharide units held by glycosidic linkages
occur in linear chains ( eg cellulose ) or branched chains ( eg glycogen )
examples : starch and cellulose made by plants
what are homopolysaccharides? give functions and egs
consists of only one type of monosaccharide units
functions:
- storage
- structural elements in plants ( cell walls ) and animal exoskeleton
examples ( locations ):
- starch ( stored energy in plants )
- glycogen ( stored extra carbohydrate in liver as quick energy )
- cellulose ( cell walls in plants )
- chitin ( outer-skeleton in animals eg losbters and shrimps )
what are lipids and what is their configuration
- biological compounds that are largely hydrocarbon in nature
when oxidised during metabolism, can yield large amounts of energy
C H O
1: >2 : 1
what are the 7 functions of lipids? give eg
EFPTEHA
- excellent energy reserves
( fat in humans ) - form the structure of cell membranes
- provide padding around organs
eg visceral fats - provide ( thermal ) insulation for our body
- are essential fatty acids ( EFA )
sources of EFA :
- fish oil ( eg salmon ), flax seed oil, almonds, walnuts, eggs etc - involved in hormone synthesis
eg lipid hormones such as testerone ( male characteristics ) ; oestrogen ( female characteristics and controls menstrual cycle ) - assist in absorption of fat-soluble vitamins
fat soluble vitamins ( vitamin A,D,E,K ) are absorbed with lipids from food into the lymph then travel around the body to be stored in fatty tissues and/or the liver. without lipids, these vitamins cant be absorbed by the body
what are proteins and its configuration ?
proteins are highly complex nitrogenous substances essential for all living systems.
perform many enzymatic functions, structural and other roles in living systems
they consist of amino acids linked together by peptide bonds
configuration : C H O N
what happens when a protein becomes denatured? give eg
a denatured protein is biologically inactive, and it is usually less water-soluble. the denaturation is usually irreversible.
eg - if egg albumin is heated, it coagulates to form a white solid ( an irreversible process )
cataract _ denatured protein in the eye ( due to UV light exposure, aging etc )
what are the 8 functions of proteins? give eg
CSCDRTSS
- catalysis ( eg enzyme, maltose, amylase )
- structure ( eg hair )
- cell movement ( eg hormone )
- defense ( eg antibody. the blood clotting proteins, fibrinogen and thrombin prevents excessive blood loss when blood vessels are damaged )
- regulation ( eg insulin and glucagon regulate blood glucose levels )
- transport ( eg haemoglobin )
- storage ( eg egg/albumin are rich sources of organic nitrogen during development )
- stress response ( eg cytochrome P450, a diverse group of enzymes found in animals and plants that usually convert a variety of toxic organic contaminants into less toxic derivatives )
what are the 2 functions of nucleic acids? give eg
PH
- protein synthesis
eg RNA ( ribonucleic acid )
- single-stranded ( one chain of nucleotide )
2. hereditary information ( pass on traits ) eg DNA ( deoxyribonucleic acid ) - double helix formation - linked through covalent and hydrogen bonds
what is a eukaryotic cell?
plants and animals cells with a nucleus and membrane-enclosed organelles
what is a prokaryotic cell?
unicellular organism without a nucleus and membrane
enclosed organelles
eg bacteria
