Chapter 1 - The Chemical Nature of Cells Flashcards
water
universal solvent
highly polar
main environment for metabolic reactions
hydrophilic / polar
dissolves readily in water
hydrophobic / non-polar
tend to be insoluble in water
pH
measure of the concentration of hydrogen ions in a solution
macromolecules
large organis molecules
what is released when monomers join together
a water molecule
monomers to these polymers: carbohydrates proteins lipids nucleic acids
monosaccharides
amino acids
fatty acids and glycerol
nucleotides
carbohydrate
COH
energy source and structural components
monosaccharide
contains one sugar unit
glucose, fructose
disaccharide
composed of two monosaccharide units
sucrose, lactose, maltose
polysaccharide
polymers of monosaccharide
usually non-polar
examples of polysaccharides
glycogen
starch
cellulose
glycogen
storage carbohydrate (glucose) in liver and muscle tissues converted to fat is in excess
starch
main form of energy source in plants
humans can digest
cellulose
main component of plant cell walls
humans can’t digest (need bacterial populations in gut)
carbohydrate condensation
monosaccharides combine to form complex carbohydrates
water is released
protein
NHCO - SP
control all metabolic processes within cells
proteome
complete set of proteins produced by a cell
how many naturally occurring amino acids? how many can humans make?
20 naturally occurring
humans manufacture 11 - rely of food for 9
amino acid structure
central carbon atom (C) hydrogen atom (H) carboxyl group (COOH) amino acid group (H2N) R group
what does the R group do in amino acids
distinguishes one amino acid from another
dipeptide
two amino acids joined together
polypeptide
macromolecule built of amino acids and linked by peptide bonds to form a single chain
peptide bond
bonds that join amino acids
protein primary structure
specific linear sequence of amino acids
protein secondary structure
the folding of the amino acid chain
alpha helices: tight coils
beta pleated sheets: folding
random loops
protein tertiary structure
the complex 3D functional shape of the protein
protein quaternary structure
two or more polypeptide chains interact to form a protein
haemoglobin
lipids
COH
fats, oils and waxes - hydrophobic
energy storage, structural component in membranes
3 types of lipids in membranes
phospholipid
glycolipid
cholesterol
phospholipid
forms structural component of the plasma membrane
glycolipid
projects out of plasma membrane
cellular communication and signalling
cholesterol
embedded and myelin sheath
maintain level rigidity
Stabilising temp
triglycerides
single glycerol molecule attached to 3 fatty acid molecules
steroids
lipids
include sex hormones and cholesterol
nucleic acids
COHNP
store info for chemical code
DNA
deoxyribonucleic acid double helix: antiparallel sugar-phosphate back bone passes genetic info through generations contained in nucleus
RNA
ribonucleic acid
3 types: m, t, r
structure of a nucleotide
five carbon sugar (ribose / deoxyribose)
phosphate group
nitrogenous base (ATGCU)
genome
sum total of the genes present in a cell or organism
mRNA
messenger RNA
carries genetic message to ribosomes where they are translated into a particular protein
tRNA
transfer RNA
molecules that carry amino acids to ribosomes where they are used to construct proteins
has anticodons
rRNA
ribosomal RNA
together with proteins, makes the ribosomes found in cytosol
found in ribosomes
protein synthesis
RNA takes the information on the DNA strand and creates the proteins necessary for life
transcription, translation
differences between DNA and RNA
R: uracil, 3 types, ribose
D: thymine, double stranded, 1 type, deoxyribose, longer
