A1.1-A1.2 Flashcards
How were the first water molecules formed?
Extremely high temperatures on the earths surface cooled down enough for water to form.
How did the first cells form?
Their thought to have come from the oceans. Because cells need a complex series of chemical reaction to form a solvent is needed. Ocean water provided that solvent.
Water is a solvent that?
- Makes up cytoplasm where all cellular reactions occur.
- Makes up fluid inside all organelles
- Permits transport in and out of the cell
- Essential to blood and other fluid in humans and other organisms
- Provides the medium for oceans, rivers, and lakes
The covalent covalent bonds between oxygen and two hydrogens are what?
Polar covalent
What is a polar covalent bond?
When two atoms have an unequal sharing of electrons
Equally shared electrons create what type of bond?
Non-polar covalent
What is a short lived attraction called?
Ephemeral or hydrogen bonds.
What is surface tension?
When the layer of molecules at the surface of water do not have water molecules above It
What is cohesion?
When molecules of the same type are attracted to each other.
Any substance that dissolves readily in water is called?
Hydrophilic
What are the tubes within a plant called?
The xylem.
Explain how tension works?
Water that evaporates in order to exit the leafs corresponding with cohesion create an area of tension.
What is adhesion?
An attraction between two unlike molecules due to hydrogen bonding
Any substance that does not dissolve readily in water is called?
Hydrophobic
Non-polar molecules (insoluble) found in nature are?
Steroid hormones (oestradiol, testosterone)- can pass through plasma membrane and nuclear membrane because of the hydrophobic similarities.
Proteins that have hydrophobic and hydrophilic sections can imbed there hydrophobic areas into the hydrophobic layers of the membrane while hydrophilic area stay attached but can interact with other substances.
Epidermal cells of leaves secret was coat the leaves and is called the cuticle. It is hydrophobic and acts as a barrier
What are the physical properties of water
- Buoyant force is equal to the weight of water displaced by the object
- Viscosity- Resistance to an object moving through it
List two examples of these properties in nature.
The ringed seal and the black throated loon.
What’s the difference between normal water and deuterium
Normal water contains hydrogen atoms with neutrons and heavy water contains hydrogen atoms that have a neutron
Explain the theory of where water originated from.
The surface of the earth was noting but magma. Then the earth could and asteroids with hydrated minerals struck the earth and released water.
What is the goldilocks zone?
An area with a suitable temperature for water to remain in its liquid form, and sufficient gravity for retaining the water
How many DNA molecules do humans have in each cell in the form of chromosomes ?
46
What is deoxyribonucleic acid (DNA)
A molecule that provides the long term genetic information of organisms on earth. (permanent)
What are the 4 nitrogenous bases?
Guanine, cytosine, Adenine, Thymine
What’s a amino acid?
Molecules that combine to form proteins.
Whats a polymer?
A large molecule composed of many sub units
What are two examples of Polymers of nucleotides?
DNA and RNA- Because they have repeating nucleotides to form the larger molecule.
What do nucleotides consist of?
A phosphate group, pentose sugar( 5 carbon monosaccharide), and a nitrogenous base.
How do nucleotides bond together?
Through condensation reactions which form covalent bonds between the sugar of one nucleotide and the phosphate group of another
What ware the five nitrogenous bases of DNA and RNA
Guanine, cytosine, Adenine, Thymine- only in DNA, Uracil- is only in RNA
Whats the difference between the bases in RNA and DNA
The bases in RNA contain ribose as their pentose sugar and the bases in DNA contain deoxyribose as their pentose sugar
How many nucleotides are there?
8
If an RNA molecule contains 322 nucleotides how many water molecules would be formed?
321
How many strands of nucleotides are in DNA and RNA
DNA consists of two strands connected by hydrogen bonds in a double helix shape. RNA consists of one strand that varies in shape
What are the complementary base pairs?
Adenine - Thymine, Cytosine - Guanine
What is RNA (ribonucleic acid)?
Does not contain permeant genetic code, except in RNA viruses
What is the molecular formula of ribose
C5H10O5
What is the molecular formula of deoxyribose?
C5H10O4
What is a hydroxyl group?
When an OH group is bonded to a carbon
What is mRNA
messenger RNA that is synthesized from genes and represents the information for protein synthesis
What is Ribosomal RNA
Along with precisely synthesized proteins, rRNA is used to create ribosomes- where protein is synthesized.
Transfer RNA (tRNA)
Special genes of DNA code for tRNA molecules. When protein is synthesized specific amino acids must be added in a specific order. tRNA makes sure to transfer the correct amino acids into the chain
What is Adenosine Triphosphate (ATP)
A single nucleotide nucleic acid used as a type of energy. When a muscle contacts many ATP molecules are the energy source of the movement
How to tell what end is the 5’ end
The first nucleotide of the strand
Whats a triple codon?
Every three bases form a triple codon
What is the first phase of protein synthesis
Transcription- This occurs when one strand of DNA is opened and a RNA molecule is synthesized using complimentary base pairing. this then synthesizes the 5’ end of the RNA first. The result in mRNA
What does the translation stage of protein synthesis entail?
The mRNA pairs with a ribosome in the cell.
What are the nitrogenous bases of DNA grouped into?
Purine and Pyrimidines
Explain a histone.
DNA wraps itself around 8 proteins in the nucleus called a histone. there then an additional histone holds it all together. The resulting structure is called a nucleosome. which then form chromosomes (humans have 46)
Group Adenine Thymine Cytosine and guanine into purines and pyrimidines
Pyrimidines- Thymine, Cytosin
Purines- Adinine, guanine
What are the differences between purines and pyrimidines
Pyrimidines are a smaller single ringed structure. Purines are larger and contain a double ring structure.
What is the Hershey- Chase experiment?
in 1952 two researchers, Alfred Hershey and Martha Chase, were unsure of the genetic material in living things. They composed an experiment using a bacteriophage and escherichia coli. They used radioactive isotope labeling( particles released during decay can be labeled) in two cultures. one with radioactive phosphorus that produced viruses that had DNA in their core. And another culture with radioactive surfer. It was detected in the protein outer coat.
They both then infected e.coli, the one with phosphorus had radioactivity decayed and the one with sulphur did not. This concluded that the genetic material was made of DNA, not protein.
What is Chargaffs rule?
late 1940 Erwin Chargaff developed a technique to show the proportions of nitrogenous bases within sources of DNA. His desperation identification technique involved paper chromatography. This concluded that the DNA contains the same number of adenine as thymine nucleotides, and well as the same ration of C-G
What is a bacteriophage
a virus that infects bacteria and is composed of a outer coat of protein and a inner core of DNA. When it infects a cell it takes over the metabolism resulting in multiple viruses being formed.
