Inside living cells

B2

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  • Created by: Belinda
  • Created on: 29-05-11 11:46

DNA

Made of 23 pairs of chromosomes

A gene codes for particular inherited characteristic

DNA molecule=two strands coild to form double helix

Linked by a series of paired bases = A-T & C-G

Intructions in the form of a code

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Protein

Organells = any structure fond in a cell with a job to perform e.g Nucleus

Organelles ribosomes are involved in protein synthesis

Protein synthesis=genetic code works by controlling when and how proteins are made in cell

Bases in DNA occur as tripletts (ACC or ACG)

Each triplet codes for a single amino acid in a protein

Stages are carried out by a chmical called RNA

RNA only has one strand and move outside nucleus into cytoplasm

RNA contains code for linking amino acids

A copy of coding strand is made to produce RNA

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Genetics & Fermentation & Microorganisms and Food

Bacteria produces the hormone insulin

Restriction enzyme cut through DNA strand to get to insulin, another restriction enzyme cuts through ring of bacterial DNA, while other enzymes insert insulin

Fermentation happens in controlled environment- fermenter

it requires: aseptic(sterile) conditions, nutrients, optimum temp, correct PH level, oxygenation- to respire, agitation(stirring) for even temp.

Yeast = single cell micro organism

In presence of oxygen it converts glucose to H2O and CO2

In absence of oxygen, it converts glucose to ethanol and CO2= fermentation

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Aerobic Respiration & diffusion

Glucose + Oxygen > Carbon dioxide + Water + Energy

Glucose and oxygen diffuse from the capilleries into respiring cells

CO2 diffuses from respiring cells into the capilleries

It is better than anaerobic respiration

Diffusion = Movement of a substance from region of high to low concentration down concentration gradient

Increased diffusion = repiration rate increases more oxygen needs to be absorbed and more carbon dioxide needs to be removed

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Anaerobic Respiration and Oxygen debt

When the lungs and bloodstream can't deliver enough oxygen to respire, the available glucos can only be partly broken down

Glucose is changed into lactic acid (waste product)

Glucose > Engery + Lactic acid

Oxygen debt is build up of lactic acid which makes muscles stop contracting efficently

Lactic acid must be broken to avoid cell damage

Lactic acid can be oxidised into Co2 + H2O

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Glossary

Cultivated = growing and nurturing an organism (often to produce or ennhance a particular feature)

Polypeptide = A single chain molecule of many amino acids joined together by peptiide bonds protein is a peptide.

Ribosome = A cell organelle nvolved in protein synthesis

Triplet = A sequence of three bases in a gene that codes for a single amino acid

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