Chapter 1 - Life Chemical, Cellular, and Evolutionary foundations Flashcards
What is observation?
the act of viewing the world around us
What is experimentation?
a disciplined and controlled way pf asking and answering questions about the world in an unbiased manner
What do observations allow us to draw?
tentative explanations (hypotheses)
What is a hypothesis?
a prediction that can be tested by observation and experimentation
What can observations do for a hypothesis?
a single observation can lead us to reject the hypothesis or support the hypothesis but cannot prove it
How do you undertake a controlled experiment?
conditions and set up kept as similar as possible for each group
researcher can then introduce differences (a variable) to see if it has an effect
Why is Evolution important in Biology?
it provides the most general and powerful explanation of how life works
What are both the living and non living worlds both subject to?
The laws of chemistry and physics
What do living things share with non living things?
All the elements that make up the living things can be found in non living things
What does carbon do?
provides the backbone of life
What are the 3 most abundant chemicals in organisms?
Carbon, Hydrogen and Oxygen
What % of known matter do hydrogen and helium make up?
99%
What elements make up most of the Earth’s crust?
Oxygen and Silicon mostly, with significant aluminium, iron and calcium
What is the first law of thermodynamics?
energy can neither be created nor destroyed: it can only be transformed from one form to another
What is the second law of thermodynamics?
the degree or disorder (or the number of possible positions and motions of molecules) in the universe tends to increase
What does entropy mean?
the amount of disorder (or the number of positions and motions of molecules) in a system
What were 2 experiments that support the hypothesis that life does not spontaneously occur?
Francesco Redi - Fly’s producing maggots on meat (open, closed, gauze)
Louis Pasteur - microbes and swan-neck flask
What is a cell?
simplest entity that can exist as an independent life unit
all cells contain a stable blueprint of information in molecular form; they have a discreet boundary that separates the interior of the cell from it’s external environment; they have the ability to harness materials and energy from the environment
What do nucleic acids do?
store and transmit information needed for growth function and reproduction
What does DNA stand for?
Deoxyribonucleic acid
What is DNA?
a double stranded helix, contains genetic material, made up of 4 bases A,T,C,G information in DNA directs formation of proteins
How is a protein formed?
Copy of DNA information to more DNA (replication)
Synthesis of RNA from a DNA template (transcription)
RNA read and Amino acids determined (translation)
what is a gene? (Protein coding)
the DNA sequence that corresponds to a specific protein product
What is one of the advantages of DNA?
it can be easily replicated and passed from cell to cell
How does replication work?
each strand of double helix serves as a template for a new strand
It is precise as if not mutations may occur from errors in DNA (altering function)
What is the plasma membrane?
separates living material within the cell from the non living environment around it
function is to control the movement of materials into and out of the cell
What is the nucleus?
houses the cell’s DNA
What does the nuclear membrane do?
selectively controls what goes in and out
What is the cytoplasm?
liquid medium of cell, place where chemical reactions occur
If a cell has no nucleus what type of cell is it?
prokaryotic
If a cell has a nucleus what type of cell is it?
eukaryotic
What are most prokaryotes?
single celled (mainly bacteria)
What types of organisms are eukaryotes?
plants, animals, fungi, and protists
In multicellular organisms what do cells do?
specialise for specific functions
What are the 3 domains of life?
Bacteria, Archaea, and Eukarya
What is metabolism?
converts energy from the environment into a form that can be used by cells chemical energy used to form/break down cells
What does ATP stand for?
Adenosine Triphosphate
What does ATP enable?
work in the cell, growth, division, active transport/cotransport (movement of substances in and out)
What is a virus?
genetic material that requires a cell to carry out it’s own functions
It is an infectious agent composed of a genome and protein coat that uses a host cell to replicate
How does Evolution occur? (natural selection)
when variation is present within a population of organisms, and when that variation can be inherited, the variants best able to grow and reproduce in a particular environment will contribute disproportionately to the next generation (natural selection), leading to a change in population over time (evolution)
What are the types of variation?
Genetic and Environmental
What is the ultimate source of genetic variation?
mutations
in what way do organisms show similarities?
in a nested pattern. e.g. humans are more similar to primates than other organisms, primates are more similar to mammals, mammals are more similar to vertebrae etc.
how can evolution be demonstrated?
lab experiments
What is environmental variation?
variation due to differences in environment
What is genetic variation?
difference in genetic material transferred from parents
What is Ecology?
the study of how organisms interact with one another and with their physical environment in nature. These interactions are in part are driven by the anatomy, physiology, and behaviour of organisms.
For what proportion of life’s history have humans lived for?
1/200 of 1% of life’s 4 billion years of history
What is the issue with humans growing numbers and contributions on the planet?
leaving a large ecological and evolutionary footprint
What are the 4 necessities of life?
metabolism, sense/adjust/evolve, reproduce with heredity, border (membranes etc.)
What is a prion?
a type of protein that can cause disease
What are some examples of diseases caused by prions?
mad cow disease and wasting disease (deer and elk)
What are the three types of RNA needed to make a protein?
mRNA (messenger), tRNA (transfer), rRNA (ribosomal)
What are the 5 kingdoms?
Bacteria, Animal, Plant, Protist, Fungi
What Elements are found in carbohydrates?
Carbon, Hydrogen, oxygen
What elements are found in Lipids?
carbon, oxygen, hydrogen (sometimes phosphorous if phospholipid)
What elements are found in proteins?
carbon, oxygen, hydrogen, nitrogen, sulfur
What elements are found in nucleic acids?
Carbon, Hydrogen, Oxygen, Nitrogen, Phosphorous
What is a monomer of carbohydrate called?
monosaccharide
What are monomers of Lipids?
Fatty acids and glycerol
What are monomers of proteins?
amino acids
What are monomers of nucleic acids?
nucleotides
What are polymers of carbohydrates (and examples)?
Polysaccharides, (starch, cellulose, glycogen)
What are some polymers of lipids?
oils and fats
waxes
cholesterol
steroid hormones
phospholipids
what are polymers of proteins?
polypeptides
What are polymers of nucleic acids?
RNA and DNA
What is the chemical structure of carbohydrates?
long chain of rings
WHat is the chemical structure of lipids?
n/a
What is the chemical structure of proteins?
primary, secondary and tertiary
What is the chemical structure of nucleic acids?
5 carbon sugar
phosphate group
nitrogenous base
What is the main function of carbohydrates?
energy
provide structure
What is the main function of lipids?
cell membrane
energy storage
What is the main function of proteins?
structural
catalyse chemical reactions
transport
What is the main function of nucleic acids?
holds information to control cellular activities
What are the bonds in carbohydrates?
Glycosidic bonds
What are the bonds in lipids?
Van der Waals forces
What are the bonds in proteins?
peptide bonds
hydrogen bonds
disulfide bonds/bridges
What are the bonds in nucleic acids?
phosphodiester bonds
hydrogen bonds
