Biology 067 -Final Review of Sections 1 to 9: Molecules of life, Cell structure and function, tissues, digestion, urinary system, cardiovascular system, blood, Defence against disease. Sectn 1: Molecules of Life Atoms to Molecules A covalent bond = electrons are shared between 2 atoms An ionic bond = an attraction of charged atoms Water and living things Hydrogen bond = the attraction of a slightly positive covalently bonded H to a slightly negative atom in the vicinity (usually oxygen) Macromolecules Macromolecules are made by joining smaller molecules (monomers) together to form longer chains called polymers – this is done through a reaction called dehydration synthesis. Hydrolysis is the reverse, it breaks down the polymers back into subunits. Carbohydrates Subunit of carbohydrate = monosaccharide All carbohydrates are composed of C,H, and O Monosaccharide’s dehydration reaction form polysaccharides Starch is a type of carbohydrate Lipids Subunits of lipids = glycerol and 3 fatty acids a specialized lipid is a phospholipids =glycerol, phosphate, 2 fatty acids –the phosphate group replaces one of the fatty acids Proteins The subunit of a protein=amino acid aa always have an amino group (NH2) and an acidic group (COOH) Amino acids form a polypeptide thru dehydration rxn aa joined by a peptide bond H
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Biology 067 -Final Review of Sections 1 to 9: Molecules of life, Cell structure and function, tissues,
digestion, urinary system, cardiovascular system, blood, Defence against disease.
Sectn 1: Molecules of Life
Atoms to Molecules
A covalent bond = electrons are shared between 2 atoms
An ionic bond = an attraction of charged atoms
Water and living things
Hydrogen bond = the attraction of a slightly positive covalently bonded H to a slightly negative
atom in the vicinity (usually oxygen)
Macromolecules
Macromolecules are made by joining smaller molecules (monomers) together to form longer
chains called polymers – this is done through a reaction called dehydration synthesis.
Hydrolysis is the reverse, it breaks down the polymers back into subunits.
Carbohydrates
Subunit of carbohydrate = monosaccharide
All carbohydrates are composed of C,H, and O
Monosaccharide’s dehydration reaction form polysaccharides
Starch is a type of carbohydrate
Lipids
Subunits of lipids = glycerol and 3 fatty acids
a specialized lipid is a phospholipids =glycerol, phosphate, 2 fatty acids –the phosphate group
replaces one of the fatty acids
Proteins
The subunit of a protein=amino acid
aa always have an amino group (NH2) and an acidic group (COOH)
Amino acids form a polypeptide thru dehydration rxn
aa joined by a peptide bond
H
The 4 levels of protein structure: primary, secondary, tertiary, quaternary
Level Shape Bonding
Primary Linear chain of aa Peptide bonds between aa
Secondary Helix (coiling) Pleated sheet (folding)
Hydrogen bonds between aa
Tertiary globular Final 3D shape and function: Ionic, covalent, hydrogen bonds btwn R groups
Quaternary (rare) All shapes All bonding – 2 or more associated polpeptides
Denaturation = changing the 3 dimensional shape of proteins – often caused by extremes in
heat or pH
Nucleic Acids
Nucleic acids are DNA and RNA
Subunit of nucleic acids =nucleotides
nucleotide =phosphate group, sugar, nitrogen base
ATP is a specialized nucleotide
ATP = nucleotide that carries energy in a high-energy phosphate bond – when that bond breaks,
energy is released
ATP = adenosine + 3 phosphate groups (adenosine=adenine + ribose a sugar)
Section 2: Cell structure and Function
Know function of various cell organelles – on diagram in text or in notes
Plasma membrane
The plasma membrane:
boundary between cell and its environment
determine which substances enter and leave a cell
contains receptor sites which determine how cell interacts with its environment
has proteins embedded in the plasma membrane
plasma membrane has:
hydrophilic heads face outside (and inside) the cell
hydrophobic tails face interior of membrane
Means of transport across the plasma membrane
Passive:
diffusion = movement of molecules from area of hi concentration to area of low concentration
osmosis - movement of water molecules from area of hi concentration to area of lower
concentration
facilitated transport - requires a concentration gradient and a protein carrier
Active
active transport – requires a carrier and energy
endocytosis occurs when a vesicle is formed (Stuff coming in)– the cell membrane invaginates
and engulfs something –transporting a large molecule inside via a vesicle
Exocytosis – transporting a large molecule to outside via a vesicle (stuff going out).
Nucleus and endomembrane system
after processing and modifying proteins and synthesizing phospholipids - ER forms vesicles to
transport proteins (from RER) and phospholipids (from smooth ER) to other parts of the cell
including the golgi
both SER and RER form vesicles
the golgi apparatus = packaging centre to get cell products ready for export
The lysosome = a vesicle with digestive enzymes for intracellular digestion
Mitochondria and cell metabolism
Mitochondria =primary source of ATP
Cell respiration in mitochondria (aerobic)
Section 3: Tissues There are 4 types of tissue:
1. Connective: binds structures together - provides structural support
2. Muscle: moves body and its parts
3. Nervous tissue -specialized for conduction of impulses
4. Epithelial: covers body surfaces and lines cavities
T cells: cytotoxic T cells against viruses and cancer
Some defntns to remember:
Pathogens = microscopic infectious agents such as bacteria and viruses which are capable of
causing diseases = any foreign substance that stimulates the immune system
Antigen = molecules found on invading pathogens that allow them to be recognized
Platelets:
Needed for blood clotting along with clotting proteins – clump at puncture site
Section 9: Lymphatic system and immunity:
Lymphatic organs:
1. Red bone marrow - active Red bone marrow in an adult is located: skull, sternum, ribs, pelvic
bones, end of long bones.
2. Thymus
3. Spleen
4. Lymph nodes
5. Tonsils
6. Peyers patches – in small intestine
7. Appendix
Immune barriers to entry:
1. Skin
2. Oil glands – secrete chemical to kill bacteria on skin
3. Cilia – in upper respiratory tract
4. Mucous – in upper respiratory tract
5. Local area bacteria in intestine
6. Acidic ph - in stomach acid – kills bacteria
Non specific defences:
1. Barriers to entry: skin, mucous, oil, stomach acid
2. Inflammatory reaction –allows phagocytotic cells to enter tissue fluid to attack pathogens
3. complement proteins =complement system also called =Protective proteins
Complement kill foreign microbes by: causing them to burst
4. Phagocytes and natural killer cells – neutrophils and monocytes (macrophages) engulf and
destroy pathogens. NK (natural killer cells) cells release perforin and inject granzymes (similar
to how cytotoxic T cells kill pathogens) into pathogen
Specific defences:
Effective against a particular infectious agent
Immune system distinguishes self from nonself
B cells:
B lymphocytes develop in the bone marrow
Represent a specific response
Are part of an antibody-mediated immunity
Protein released by B cells= antibodies
Antibodies are proteins released from plasma cells (B cells) to fight infections
Unlike T cells, B cells DO NOT require antigen-presenting cell
T cells
Lymphocytes travel to the thymus to become mature T lymphocytes
T cells recognize antigens because they are activated by antigen presenting cells
Cytotoxic T cells produce perforin to punch holes in invading pathogen
Apoptosis =programmed cell death (PCD) once the threat of infection passes – development of
new plasma cells stop and those present undergo apoptosis because they are no longer needed
Comparison of specific immune responses between B cell and T cell immunity:
B cell T cell
Where produced Red bone marrow Red bone marrow Where mature Red bone marrow Thymus Type of mediated response Antibody mediated response Cell mediated response Antigen recognition mechanism
B cell receptor recognizes nonself
Antigen presenting cells
response -Clonal expansion to form plasma cells to produce antibodies -Memory B cells
-Cytotoxic T cells -helper T cells to help B cells -memory T cells
Acquired immunity:
Active
Long lasting
Either produced by own body or induced by vaccines Passive
Temporary
Individual given prepared antibiotics
Antibodies in mother’s milk = example of passive immunity