Cell Biology - 1.4, 1.5, 1.6 Flashcards
What is each protein built up from?
a large number of subunits called amino acids.
What are amino acids joined together in?
chains
What is the function of proteins?
Proteins have many functions such as structural, enzymes, hormones, antibodies and receptors.
What do enzymes function as?
biological catalysts
What are enzymes made by?
all living cells. (several chains of amino acids)
What do enzymes do?
they speed up chemical reactions and are unchanged in the process.
The shape of the active site of an enzyme molecule is…
complementary to its specific substrate(s).
How is an active site exposed?
It is made up of several chains of amino acids folded and coiled in a particular way that exposes an active site.
What does enzyme action result in?
product(s)
What reactions can enzymes be involved in?
Degradation or synthesis reactions
What does a degradation reaction do?
Converts a substrate to products. large—> small
What does a synthesis reaction do?
Converts substrates to a product.
small—>large
During a degradation or synthesis reaction, what forms and what does this do?
an enzyme-substrate complex forms, facilitating the reaction.
Be able to draw diagrams and word equations for degradation and synthesis reactions.
Synthesis
glucose-1-phosphate
phosphorylase
——————–>
starch
Degradation
Starch
amylase
———->
maltose
Name two enzymes and their substrate(s) and produt(s)
Phosphorylase: glucose-1-phosphate, starch
Amylase:starch, maltose
When is each enzyme most active?
In its optimum conditions.
What can enzymes, and other proteins be affected by?
temperature and pH
Enzymes can be denatured, what will this result in?
in a change in their shape which will affect the rate of reaction.
Where can genetic information be transferred from?
from one cell to another by genetic engineering.
What is an organism that has been ‘reprogrammed’ described as?
genetically modified
What are the stages of genetic engineering?
1.Identify section of DNA that contains the required gene from source chromosome.
2.Cutting off the source chromosome using a special enzyme (acting as biochemical scissors).
3.Extract required gene
4.Extract plasmid from bacterial cell
5.Insert and seal required gene into bacterial plasmid
6.Insert plasmid into host bacterial cell to produce a genetically modified (GM) organism.
What can humans use genetic engineering to get?
organisms to produce proteins which they would not normally produce.
What does the use of enzymes in this process do?
Cut and seal DNA.
What must the chemical energy stored in glucose be released by?
all cells through a series of enzyme-controlled reactions called respiration.
What is the energy released from the breakdown of glucose is used to do?
generate ATP
What can the energy transferred by ATP can be used for?
cellular activities
What are some examples of cellular activites that require ATP?
muscle cell contraction, cell division, protein synthesis and transmission of nerve impulses.
What is glucose broken down to and what does this release?
2 pyruvate molecules releasing enough energy to yield two molecules of ATP.
What does further breakdown depend on?
the presence/abscence of oxygen
If oxygen is present what takes place?
aerobic respiration
If aerobic respiration takes place, what happens?
each pyruvate is broken down to carbon dioxide and water, releasing enough energy to yield a large number of ATP molecules.
What is the word summary of the process of aerobic respiration?
Glucose + oxygen —> carbon dioxide + water + energy
If there is an absence of oxygen what takes place?
the fermentation pathway
In animal cells, what happens if the fermentation pathway takes place?
the pyruvate molecules are converted to lactate
What does the breakdown of each glucose molecule via the fermentation pathway yield?
only the initial two molecules of ATP.
What is the word summary of the fermentation pathway process in animal cells?
Glucose —> lactate + energy
What is the word summary of the fermentation pathway process in plant and yeast cells?
Glucose —> carbon dioxide + ethanol + energy.
Where does respiration begin?
the cytoplasm
Where is the process of fermentation completed in?
the cytoplasm
Where is the process of aerobic respiration completed in?
the mitochondria
The higher the energy requirement of a cell the greater…
the number of mitochondria present in that cell.
