BSCI 124 Study Guide - Midterm Guide: Cell Wall, Lipid Bilayer, Fluid Mosaic Model
30 Apr 2018
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L2: The Amazing Plant Cell
All share the following:
o Carbon-based
o Formed from a few elements: C, H, O, P, N
o Modular construction
o Function depends on structure
The cell is made up of:
Carbohydrates (sugars, starches, cellulose)
o Organic molecule composed of C, H, O (1:2:1)
o Most abundant of life’s molecules
o Function:
– Energy storage
– Structure in plants
– Carbon sources to make other molecules (nucleic/amino acids)
Three types:
o Mono- saccharides (one)
– CnH2nOn
– Glucose C6H12O6 (blood sugar)
– Fructose C6H12O6 (fruit)
– Ribose C6H12O6 (nucleic acid)
o Di- saccharides (two)
– Composed of two monosaccharides
– Sucrose C12H22O11 (table sugar)
– Maltose (two glucose)
– Lactose (milk)
o Poly- saccharides (many)
– Long chains of monosaccharides
– Starch: energy storage
– Cellulose: plant cell walls (wood, paper, cloth)
Lipids (fats, oils, waxes, phospholipids, steroids)
o Diverse group of organic compounds
o Usually composed of C, O, H atoms (sometimes P)
o Function:
– High-energy food
– Part of cell membrance
– Waxes, hormones, vitamins, pigments
o Energy storage of lipids:
– Monoglycerides (glycerol + 1 fatty acid chain)
– Diglycerides (monoglyceride + 2nd fatty acid chain)
– Triglyceride (diglyceride + 3rd fatty acid chain)
find more resources at oneclass.com
find more resources at oneclass.com
Three types:
o Fats, oils, waxes
– Made from two building blocks: Glycerol molecule, fatty acids
– Water insoluble
– Fats are solid at room temperature (lard, butter)
– Oils are liquid (corn oil, peanut oil, olive oil)
o Phospholipids
– Contain phosphorus (a phosphate group)
– Makes head hydrophilic (water loving), fatty acid chain is hydrophobic (water
hating)
– The membranes of cells is a lipid bilayer
o Steroids
– Structurally different from other lipids
– Composed of 4 carbon rings and side groups
– Include sex hormones, cortisol, cholesterol and others
Proteins (composed of amino acids)
o Large complex molecules
o Composed of C, H, O, S and N
o Function:
– Building blocks of cell (amino acids-20)
– Helps control what passes through plasma membrane
– Animal structure (hair, nails, tendons, muscles)
– Enzymes to speed up chemical reactions
Nucleic Acids (DNA, RNA)
o Large organic molecules
o Composed of C, H, O, P, N
o Basic unit is the nucleotide: a sugar, a phosphate, and a nitrogenous base
o DNA: Deoxyribonucleic acid, carries information about the entire cell
o RNA: Ribonucleic acid, a copy of DNA
o ATP: Has a role of energy transfer/exchange
o Function:
– Information storage (DNA, RNA)
– Energy carrier (ATP)
Cell Theory
o Cell is the basic unit of life
o Organisms are composed of cells
o Cells arise from other cells
Two types:
o Prokaryotic- Simple cells, lack organelles
– Ex: bacteria
– 10-100 times smaller than animal or plant cells
o Eukaryotic- Have organelles: nuclei, mitochondria, etc.
– Cells of plants, animals, fungi
– Some unicellular organisms: algae, amoeba, etc.
find more resources at oneclass.com
find more resources at oneclass.com
Plants vs. Animal Cells
o Plant cells have 4 things animal cells do not:
– Cell walls
– Chloroplasts
– Plasmodesmata
– Vacuoles
Plant Cells
o Structural building blocks to form tissues and organs
o Potentially can function independently
o Can create a whole plant from a single cell (plant cloning)
Outside of a Plant Cell
o Cell wall- Protects and supports the cell
– Made of mostly cellulose
– Allows water and other molecules to pass through (like cardboard)
▪ Primary wall- formed early, located on the outermost layer
▪ Secondary wall- Deposited on the inside, between primary cell wall and
plasma membrane
▪ Middle lamella- What glues adjacent cells together
o Plasma/Cell membrane- Lipid bi-layer
– Hydrophilic “heads” (outer), hydrophobic “tails” (inside)
– Differentially permeable: lets water pass through, but not other molecules
– Fluid mosaic model- A double layer of phospholipids with scattered proteins
o Plasmodesmata- Cytoplasmic connections between adjacent cells
– Allow for the movement of materials form cell to cell
Inside the Plant Cell
o Cytosol- A matrix of water (90%), proteins, organic molecules, ions
o Cytoplasm- Cytosol and organelles only (except nucleus)
o Protoplast- Everything inside the cell wall (plasma membrane, cytosol, organelles)
o Cytoskeleton- Made up of microtubules and microfilaments
– Network of protein cables that provide structural support to the cell- they help in
cell division and elongation
– Important for mitosis, cell division
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
All share the following: carbon-based, formed from a few elements: c, h, o, p, n, modular construction, function depends on structure. Carbohydrates (sugars, starches, cellulose: organic molecule composed of c, h, o (1:2:1, most abundant of life"s molecules, function: Carbon sources to make other molecules (nucleic/amino acids) Three types: mono- saccharides (one, di- saccharides (two) Cellulose: plant cell walls (wood, paper, cloth: poly- saccharides (many) Lipids (fats, oils, waxes, phospholipids, steroids: diverse group of organic compounds, usually composed of c, o, h atoms (sometimes p, function, energy storage of lipids: Monoglycerides (glycerol + 1 fatty acid chain) Diglycerides (monoglyceride + 2nd fatty acid chain) Triglyceride (diglyceride + 3rd fatty acid chain) Made from two building blocks: glycerol molecule, fatty acids. Fats are solid at room temperature (lard, butter) Oils are liquid (corn oil, peanut oil, olive oil) Makes head hydrophilic (water loving), fatty acid chain is hydrophobic (water. The membranes of cells is a lipid bilayer.
