Cell components
The centre of the nucleus is called:
The nucleolus
The cell transport method that requires no energy is called:
Of a proton, neutron and electron, which has the negatice charge?
Electron
Which of these is the strongest type of bond?
Ionic bond, hydrogen bond, covalent bond.
Covalent bond.
Acids/bases release H+ ions.
Acids
True or false: The cells found in your lungs have a cell wall.
What does a semi-permeable membrane do?
Enable the transport of one substance while preventing the diffusion of the solute.
The mass of an atom is made up from:
Protons and neutrons only; not electrons.
Surface tension is an example of which type of bond?
Hydrogen bond
List three types of carbohydrates:
Monosacchirides (fructose, glucose)
Disacchirides (Sucrose, lactose, maltose)
Polysacchirides
What part of the cell synthesises carbodhydrates?
The golgi apparatus
A hypotonic solution has more/less water than cells.
More
Define valency.
An atom's ability to combine with other atoms.
A chemical reaction indicated with two arrows (one beneath the other) in opposite reactions signifies a reversible/ irreversible reaction.
Reversible.
Are electrolytes organic or inorganic compounds? What are they important for?
Inorganic. They are important for nervous transmission, electrical cardiac activity and skeletal muscle function.
In the mitochondria, chemical energy is converted to what?
Adenosine tri-phosphate (ATP)
It may require a pump, such as the Na/K pump.
A salt is formed by:
The attraction between opposite charges of bonded ions. These bond together to form a compound claled a salt.
What is the name for energy that is stored?
Potential energy
What components of phospholipids are hydrophobic/ hydrophilic?
Head = hydrophilic
Tail = hydrophobic
Ribosomes
List three things that the process of endocytosis needs:
2. Plasma membrane
3. Intracellular vesicle
A sodium atom has 11 protons and 11 electrons. It combines with chloride, donating an electron. It is now positively/negatively charged.
Positively charged.
Describe a polar covalent bond.
When atoms with different electronegativities share electrons in a covalent bond. The electronegativty of the bigger atom will increase as the atom pulls the electrons to itself, decreasing the electronegativity of the ones it dragged to itself.
Briefly describe protein synthesis.
1. RNA polymerase unwinds DNA from its tightly coiled state and generates an RNA strand complimentary to the template DNA
2. Mature mRNA is formed when introns are spliced out, consisting only of exons. It leaves the nucleus via the nuclear pore.
3. tRNA brings amino acids. Binding between complimentary anticodons and codons results in insertion of amino acid into the sequence. This occurs in the ribosomes, and forms a polypeptide.
4. Polypeptide sequence returns to the cytoplasm for further processing into a protein.