Life Science Flashcards
the four basic macromolecules
carbohydrates, nucleic acids, lipids, and proteins
macromolecules are _______ which are larger molecules comprised of smaller molecules called _________
polymers, monomers
monomers are joined together by a dehydration reaction, which is an _______ (energy requiring) rxn so-called bc it releases a molecule of water
endothermic
the bonds in a polymer can be broken by a _____ rxn
exothermic (energy releasing) reaction, and H20 is broken down to join monomers H+ and OH
carbohydrates (sugars) are made up of what?
carbon, hydrogen and oxygen
monomers of carbohydrates are called what? and have these elements in the ratio _______
monosaccharids, CnH2nOn
Common monosaccharides include?
glucose and fructose
monosaccharides join together to form?
disaccharides (sucrose, lactase), and polysaccharides
monosaccharides and polysaccharides can join together to form complex branching molecules called _______
oligosaccharides
bodily uses for carbohydrates?
fuel sources (glycogen, amylose)
means of communication b/w cells (glycoproteins)
cell structure and support (cellulose, chitin)
lipids (fats) are composed of what?
mainly of hydrogen and carbon
functions of lipids?
make up the outer structure of cells (phospholipids), and can act as fuel, as steroids, and as hormones. Lipids are hydrophobic (repel water)
two types of cholesterol? which is good, and which is bad?
High-density lipoprotein (HDL) and Low-density lipoprotein (LDL)
HDL is good, LDL is bad
functions of proteins?
enzymes: DNA replication, cellular division, cellular metabolism
structural proteins: rigidity to cartilage, hair, nails, and the cytoskeletons
communication b/w cells, and transportation of molecules
proteins are made up of individual ______. each of which has what?
amino acids - each of which has an amino group, and carboxylic acid group, along with other side groups
amino acids are joined together by what type of bonds? when they join they become?
peptide bonds and when they join in this way they become polypeptides
how many amino acids are there?
20
each nucleotide includes what?
a pentose sugar, a phosphate group, and a nitrogenous base
what is a codon?
a sequence of three nucleotides that together form a unit of genetic code in a DNA or RNA molecule. Each codon codes for a specific amino acid.
what are the four nitrogenous bases found in DNA?
thymine, cytosine (pyrimidines)
adenine, guanine (purines)
what is the one different nitrogenous base for RNA?
thymine is replaced by uracil
DNA is made from the sugar _______, and RNA is made from the sugar ______
deoxyribose (DNA), ribose (RNA)
together, all the codons needed to make a specific protein are called a _______
gene
When a protein is produced the two sides of the DNA helix unwind, and a complementary strand of __________ is manufactured using the DNA as a template (a process called _______). This mRNA then travels outside the nucleus where it is “read” by ________ (a process called ______)
messenger RNA (mRNA)
transcription
read by a ribosome, a process called translation
each codon is matched to a _______, which carries a specific _________. The sequence of ______ is then joined together to form a _________
anti-codon, amino acid
amino acids is then joined together to form a polypeptide
when it is not being transcribed, DNA is tightly wound around proteins called __________ into packages called _________. Chromatin is further packaged into packages of DNA called _________. During cell division, DNA is replicated to create two identical copies of each ________ called ________.
Histones, Chromatin
Chromosomes
Chromosomes, called chromatids
What are the first four phases of the cell cycle? And what is this stage called collectively? This stage comes before what? In other words these phases are not a part of mitosis (when the cell is actively dividing)
Interphase
Go (Growth phase 0)
G1 (organelles are duplicated)
S phase (DNA synthesis) - genetic material is duplicated
G2 phase (additional growth and protein production)
