Topic 2 Flashcards
How has the lungs adapted for gas exchange?
-Lots of alveoli, creates larger S.A to Volume for diffusion
-Alveoli and capillary endotheliums are 1 cell thick
-Good supply of blood
-Breathing in and out, refresh air -> maintain concentration gradient
Structure of a phospholipid + its properties
-Phosphate head, attracts water
-2x Fatty Acid Tails, repels water
What is faciliated diffusion?
-Diffusion for larger and charged particles
-Across a membrane, down the concentration gradient
-Passive process
Explain active transport
-Movement of substances against a concentration gradient
-A molecule attaches to the carrier protein
-It changes shape and moves the molecule across a membrane, releasing it
-Uses ATP as energy, produced by respiration
-ATP is hydrolysed for use
Explain endocytosis
-A cell membrane can surround substance
-Membrane pinches off in the inner, forming a vesicle
-Uses ATP for energy, accessed by hydrolysis
Explain exocytosis
-Vesicles containing substance pinch off sacks of the golgi apparatus to the cell membrane
-Vesicle fuses into the membrane, releasing contents out of the C.M
Structure of a protein
-Made from mono/polymers of amino acids
-Which join together through a condensation reaction
-Forming peptide bonds
Explain globular protein structure
-Globular proteins are round, compact
-Made of multiple polypeptide chains
-Coiled up, hydrophillic parts on outside and hydrophobic on inside
-Protein is soluble, easy for transportation
-E.g Haemoglobin
Explain fibrous 3d protein structure
-Fibrous proteins are made of long, insoluble polypeptide chains
-Polypeptide chains held together by many bonds (disulfide, H)
-Strong and long, can be found in supportive tissues
-E.g Collagen
Explain enzymes
-Is a biological catalyst
-Is a protein
-Have an active site, which has specific shape where substrate molecules bind to
-Lower the activation energy of a reaction
Explain RNA
-RNA is similar to DNA
-RNA transfers genetic information from DNA to ribosomes
-Its nucleotide has a ribose sugar
-Are polymers of mononucleotides
Explain nucleotides
-Pentose Sugar (5C Sugar)
-Nitrogen-containing organic base
-Phosphate group
-Make up DNA and RNA
-Phosphodiester bonding
Explain DNA
-DNA stores genetic information
-Are polymers of mononucleotides
-Its nucleotide has a deoxyribose sugar
-TAGC bases
Explain mRNA
-Messenger RNA is made in the nucleus, during transcription
-3 adjacent bases = codon
-Carries genetic code from DNA in nucleus to cytoplasm, for translation into a protein
Explain tRNA
-Transfer RNA is in the cytoplasm
-Has amino acid binding site
-Has a sequence of 3 bases, a complementary anticodon
-Carries amino acids to ribosomes during translation