Term
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Definition
| the amount of energy it takes to heat one gram of water by one degree. 1 cal = 4.2J |
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Term
| How is enzyme activity regulated? |
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Definition
| Gene expression level of enzyme and proteolysis which switch the enzyme off/on by chemical modification (e.g. phosphorylation) or interaction with products/other metabolites |
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Term
| Where can ATP be obtained from? |
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Definition
| Catabolising sugars (glucose), fat and proteins (last resort) |
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Term
| What is produced for every glucose molecule? |
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Definition
| 2 pyruvic acid molecules and thus 2 acetyl-coA |
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Term
| What is the electrochemical membrane potential? |
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Definition
| the sum of all electrical and chemical potentials |
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Term
| how many ATP are formed from how many protons? |
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Definition
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Term
| How and where is most ATP produced? |
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Definition
| ATP is formed via oxidative phosphorylation using energy stored as a protein gradient via the electron transport chain |
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Term
| The body maintains a glucose concentration of... |
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Definition
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Term
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Definition
| Muscle and liver as glycogen |
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Term
| How does glucose enter the bloodstream |
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Definition
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Term
| What is the bodys response when glucose is abundant? |
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Definition
| converts it to glycogen via glycogensis |
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Term
| What is the body response when glucose is needed? |
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Definition
| Glucose is formed from glycogen by glycogenolysis |
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Term
| Describe the structure of glycogen |
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Definition
| Highly branches polymer with many ends (made up of 120,000 glucose units) |
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Term
| What are the key enzymes of glycogen metabolism? |
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Definition
| Glycogen synthase and glycogen phosphorylase |
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Term
| What does glycogen synthase do? |
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Definition
synthesis glycogen from glucose-1-phosphate in response to insulin
GLYCOGENSIS |
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Term
| What does glycogen phosphorylase do? |
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Definition
Breaks down glycogen in response to glucagon or adrenaline
GLYCOGENOLYSIS |
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Term
| Why glycogen metabolism be tightly maintained and how is it? |
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Definition
As both synthesis and degradation of glycogen are exergonic (loses energy)
-hormones
-glucose availability
-energy status (ATP) |
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Term
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Definition
a small polypeptide secreted by beta cells that promotes dephosphorylation.
secreted in response to high blood glucose
target tissues: adipose tissue, muscle and liver |
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Term
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Definition
glucagon signals the need to release more glucose into the blood
secreted by alpha cells
target tissue is the liver
promotes glycogen breakdown and new glucose synthesis |
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Term
| How are metabolic enzymes controlled? |
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Definition
| phosphorylation (in repsonse to hormonal signals) |
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Term
| Describe the mechanism for glycogenolysis |
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Definition
Glucagon/adrenaline
-> ATP activates cAMP
-> protein kinase A activated
-> PKA adds a phosphate group to phosphorylase kinase
-> phos-phorylase a (active form) breaks down glycogen into glucose |
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Term
| How to glycogen storage diseases (GSD) arise? |
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Definition
| missing or deficient enzymes |
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Term
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Definition
uses lactate/pyruvate and oxaloacetate to make glucose in the liver
recycles amino acid backbone into glucose
(when glycogen is used up) |
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Term
| How do RBC's receive ATP? |
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Definition
Glycolysis.
They have no mitochondria (thus consume no oxygen) |
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Term
| What abnormal environment do tumour cells live in and why? |
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Definition
| Highly acidic due to incredibly high (x200) glycolysis rate (which produces lactate) |
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Term
| what is lipolysis? give an example |
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Definition
| when lipids are broken down using lipoprotein lipase (e.g. TACs broken down into fatty acids so they can cross the cell membrane) |
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Term
| How are lipids transported in the blood? |
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Definition
| in molecules known as lipoproteins (with TAC in the middles) |
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Term
| What occurs when two amino acids combine? |
|
Definition
a peptide chain and water molecule is produced
N-Ca-C'..N-Ca-COOH |
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Term
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Definition
a protein in skeletal red muscle tissue that 'grabs' the oxygen released from haemoglobin.
alpha helical protein. |
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Term
| Why are disulphide bonds not found on intracellular proteins? |
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Definition
They are formed via oxidation
Cytoplasm is a reducing environment |
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Term
| Describe the secondary structure: a-helix |
|
Definition
| Hydrogen bonds form between the "N" on a main chain of one residue and teh carboxyl oxygen on the "C" of another residue |
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Term
| Describe the secondary structure: b-sheet |
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Definition
| hydrogen bonds form between neighbouring beta strands. Can be parallel or antiparallel |
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Term
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Definition
| self contained structural unit within proteins that can fold up independently |
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Term
| Describe the tertiary structure of a protein |
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Definition
| The overall three-dimensional shape of an entire protein molecule |
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Term
| Describe the quatenary structure of a protein |
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Definition
| Many proteins are made up of multiple polypeptide chains, often referred to as protein subunits. These subunits may be the same (as in a homodimer) or different (as in a heterodimer). The quaternary structure refers to how these protein subunits interact with each other and arrange themselves to form a larger aggregate protein complex. |
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Term
|
Definition
carries the genetic code
single stranded |
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Term
|
Definition
| involved in translating the code |
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Term
| Describe the relationship between sugar phosphate and base |
|
Definition
Bases attach to the first carbon of the sugar
phosphate group attaches to the fifth and links sugars covalently by the third |
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Term
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Definition
| the building blocks of nucleic acids, nucleotides are composed of a nitrogenous base, a five-carbon sugar (ribose or deoxyribose), and at least one phosphate group. |
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Term
| How are chromosomes formed? |
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Definition
Eukarotic nDNA is complexed with proteins to form chromatin
chromatin condenses further to form chromosomes |
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Term
| What are the 2 secondary rna structures |
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Definition
|
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Term
|
Definition
| the template used in protein synthesis |
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Term
|
Definition
| carries amino acids to the protein synthesis machinery |
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Term
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Definition
| the major component of 'ribosomes' the site at which protein synthesis takes place |
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Term
| What is DNA polymerase and how does it work? |
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Definition
enzyme used to make new DNA. Binds to the short double stranded region of nucleic acids and slides along to the slightly free end. Then adds nucleotide units.
Can also fix its mistakes during 'proof reading' by sliding backwards to remove and forward to replace. |
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Term
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Definition
| makes a small region of complimentary RNA (called a primer) which provides enough double stranded nucleic acid for DNA polymerase to bind to |
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Term
| What is RNA polymerase and how does it work? |
|
Definition
enzyme used to make new RNA.
binds to the promoter region of the gene and moves along separating the two strands and a nucleotide binds behind the RNApol, new strand moves away and the dna strand rezips |
|
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Term
| what is a termination site? |
|
Definition
| region of DNA that tell RNApol to stop making mRNA |
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Term
|
Definition
| recognises a specific codon and carries an amino acid related to that codon. |
|
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Term
| Where do you find codons and anticodons? |
|
Definition
codons = triplet in DNA and mRNA
anticodon = triplet in tRNA |
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Term
| What is the relevance of ribosomes? |
|
Definition
| they are the site of translation in the cytoplasm and make protein chains |
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Term
| How is translation initiated? |
|
Definition
1. binding of small ribosomal subunit to mRNA
2. biding of initiator tRNA to mRNA
3. binding of large ribosomal subunit to mRNA
4. binding of tRNA with 2nd amino acid to the A site
5. covalent bond forms between initator codon and 2nd amino acid |
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Term
| If a cell lacked the enzyme DNA polymerase, it could not |
|
Definition
| form complementary sequences of DNA. |
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Term
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Definition
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Term
|
Definition
| RNA is synthesized from DNA in the nucleus |
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Term
| A high-energy bond in ATP is present... |
|
Definition
between the first and second phosphate group.
between the second and third phosphate group. |
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Term
| The mRNA sequence that is complementary to the sequence ATC on DNA is |
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Definition
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Term
| The dense layer of connective tissue that surrounds an entire skeletal muscle is the |
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Definition
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|
Term
| The plasma membrane of skeletal muscle is called the |
|
Definition
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Term
| Muscle fibers differ from "typical cells" in that muscle fibers |
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Definition
| Correct have many nuclei. |
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Term
| The action potential is conducted into a skeletal muscle fiber by |
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Definition
|
|
Term
| Each thin filament consists of |
|
Definition
| two protein strands coiled helically around each other. |
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Term
When calcium ion binds to troponin,
... |
|
Definition
| tropomyosin moves into the groove between the helical actin strands. |
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Term
| titin is a protein that accounts for... |
|
Definition
| elasticity of resting muscle |
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Term
| Each skeletal muscle fiber contains ________ myofibrils. |
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Definition
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