Cells. Variation and Function of Cells

Transcription

1 Cells Variation and Function of Cells

2 Plasma Membrane= the skin of a cell, it protects and nourishes the cell while communicating with other cells at the same time. Lipid means fat and they are hydrophobic Hydrophobic- (water fearing) nonpolar and does not dissolve in water Hydrophilic- (water loving) polar molecules that do dissolve in water. Amphiopathic- Have both hydrophobic and hydrophilic parts.

3 Lipid Bilayer- the cell membrane is made up of phospholipids that arrange themselves into two parallel layers with the phosphate heads facing the internal cytosol and the external environment and the hydrophobic tails sandwiched in between. The membrane then has two outer hydrophilic layers and an inner hydrophobic layer which prevent the entrance of nearly all large molecules and charged or polar molecules The membrane has several proteins that pass through it creating channels that only allow a specific ion or molecule to cross the membrane.

4 Fig. 7-7 Fibers of extracellular matrix (ECM) Glycoprotein Carbohydrate Glycolipid EXTRACELLULAR SIDE OF MEMBRANE Cholesterol Microfilaments of cytoskeleton Peripheral proteins Integral protein CYTOPLASMIC SIDE OF MEMBRANE

5 Fig. 6-30a Collagen EXTRACELLULAR FLUID Proteoglycan complex Fibronectin Integrins Plasma membrane Microfilaments CYTOPLASM

6 Fig. 6-7 Outside of cell (a) TEM of a plasma membrane Inside of cell 0.1 µm Carbohydrate side chain Hydrophilic region Hydrophobic region Hydrophilic region Phospholipid Proteins (b) Structure of the plasma membrane

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10 Trans-membrane proteins have hydrophilic ends and a hydrophobic center which keeps them locked into the cell membrane Diffusion- the process of solute particles spreading out to equilibrium Passive transport is the movement of a solute down its concentration gradient. Channel proteins provide a path for solute movement only. Carrier proteins change shape when they bind to substrate going from being open to one side to being open to the other

11 Fig. 7-8 N-terminus EXTRACELLULAR SIDE C-terminus α Helix CYTOPLASMIC SIDE

12 Fig EXTRACELLULAR FLUID Channel protein (a) A channel protein Solute CYTOPLASM Carrier protein Solute (b) A carrier protein

13 Osmosis- the process of water spreading out or moving to reach equilibrium Aquaporins are one channel protein specific to water Semi permeable- the membrane is able to decide what passes through the membrane Concentration Gradient- the movement of a solute from high concentration to low concentration

14 Tonicity: The ability of a solution to cause a cell to lose or gain water. Saline solution used to clean wounds and contacts. Saline means Salt but it is isotonic in concentration to tears and body fluid to protect cells. Because water is passively transported, the addition of hypotonic water to a cells environment will cause the cell to swell. The addition of hypertonic solution to a cells surrounding will cause the cell to shrink. In a plant, swelling from the hypotonic environment provides support.

15 Fig Hypotonic solution Isotonic solution Hypertonic solution H 2 O H 2 O H 2 O H 2 O (a) Animal cell Lysed Normal Shriveled H 2 O H 2 O H 2 O H 2 O (b) Plant cell Turgid (normal) Flaccid Plasmolyzed

16 Active transport is the movement of a solute which requires an input of energy, often because the solute is moving against its concentration gradient. H+ pumps or Na/K pumps both build a charge on one side of the membrane and keep adding to that charge. They must use ATP or other energy to do this. Membrane potential- the charge across the cell membrane Solute- the material that is dissolved in a solution Solvent- The material that does the dissolving in a solution

17 Fig EXTRACELLULAR FLUID [Na + ] high [K + ] low Na + Na + Na + Na + Na + Na + Na + Na + CYTOPLASM 1 Na + [Na + ] low [K + ] high 2 P ADP ATP 3 P P P

18 Co-transport is tricky because the protein itself uses no energy but it relies on a gradient that does. A solute that would not normally move across the membrane is allowed to because it is accompanied by a molecule that is moving down its concentration gradient. Endocytosis- taking large materials into a cell Exocytosis- kicking large materials out of a cell Phagocytosis is endocytosis that takes in a large amount of solid material from the outside environment.(cell eating) Pinocytosis is endocytosis that take in a large amount of liquid from the environment surrounding the cell.

19 Fig ATP + + H + H + H + Proton pump H + + H + Sucrose-H + cotransporter + H + H + Diffusion of H + H + Sucrose + + Sucrose

20 Fig. 6-14a Nucleus 1 µm Lysosome Lysosome Digestive enzymes Plasma membrane Digestion Food vacuole (a) Phagocytosis

21 Fig. 6-14b Vesicle containing two damaged organelles 1 µm Mitochondrion fragment Peroxisome fragment Peroxisome Lysosome Vesicle Mitochondrion Digestion (b) Autophagy

22 Endomembrane System Evolution- is the idea that the endomembrane system of eukaryotes resulted from a primitive ancestor that developed membrane folds to increase surface area. Over time, that folding pattern became more and more complex in its form and function leading to the ER and Golgi s development.

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24 Monomers are simple molecules that can be linked into chains. (Nucleotides, Amino acids, monosaccharides) Polymers are the long chains of monomers. (DNA, RNA, Cellulose, Protein, Glycogen) Polymers are the most common forms of macromolecules in the body Monomers are hooked together to form polymers through a process called a condensation reaction. These reactions require a H to be removed from one monomer and an OH from another monomer to form water.

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27 Monosacharides are monomers that consist of of carbon atoms, each of which has a hydrogen on one side and an OH group on the other. Polysaccharides are long chains of sugars that are covalently joined together Carbohydrates are a term that refer to polysaccharides, starches, and monosacharides (as long as they re digestible) Nucleic Acids- includes both RNA and DNA, both are made up of nucleotides

28 Fig. 5-3a Trioses (C 3 H 6 O 3 ) Pentoses (C 5 H 10 O 5 ) Hexoses (C 6 H 12 O 6 ) Glyceraldehyde Ribose Glucose Galactose

29 Fig glycosidic linkage Glucose Glucose (a) Dehydration reaction in the synthesis of maltose Maltose 1 2 glycosidic linkage Glucose Fructose Sucrose (b) Dehydration reaction in the synthesis of sucrose

30 Fig. 5-6 Chloroplast Starch Mitochondria Glycogen granules 0.5 µm 1 µm Amylose Glycogen Amylopectin (a) Starch: a plant polysaccharide (b) Glycogen: an animal polysaccharide

31 Fig. 5-7bc (b) Starch: 1 4 linkage of glucose monomers (c) Cellulose: 1 4 linkage of glucose monomers

32 Nucleotides- These are the monomers that are used to make DNA and RNA. Nucleotides all contain 1 sugar, 1 phosphate, and 1 nitrogenous base.

33 Fig. 5-27c-1 Nitrogenous bases Pyrimidines Cytosine (C) Thymine (T, in DNA) Uracil (U, in RNA) Purines Adenine (A) Guanine (G) (c) Nucleoside components: nitrogenous bases

34 Fig. 5-27c-2 Sugars Deoxyribose (in DNA) Ribose (in RNA) (c) Nucleoside components: sugars

35 Fig C 5 end Nitrogenous bases Pyrimidines 3 C Nucleoside Nitrogenous base Cytosine (C) Thymine (T, in DNA) Uracil (U, in RNA) Purines 5 C 3 C Phosphate group (b) Nucleotide Sugar (pentose) Adenine (A) Guanine (G) 3 end Sugars (a) Polynucleotide, or nucleic acid Deoxyribose (in DNA) Ribose (in RNA) (c) Nucleoside components: sugars

36 Fig ' end 3' end Sugar-phosphate backbones Base pair (joined by hydrogen bonding) 3' end Old strands Nucleotide about to be added to a new strand 5' end New strands 3' end 5' end 5' end 3' end

37 Proteins are the most common base chemical for enzymes, they are made from Amino acids that are put together in a very specific sequence that is coded for by RNAs that were made from the code in DNA. Proteins have a Nitrogen and Carbon spine with varying side chains that determine their behavior.(c-c-n-c-c-n-c-c-n) Amino Acids are the monomers of protein. All have the same structure with the exception of the R group. There are two carbons and a nitrogen atom acting as the base of the molecule.

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39 Fig Nonpolar Glycine (Gly or G) Alanine (Ala or A) Valine (Val or V) Leucine (Leu or L) Isoleucine (Ile or Ι) Methionine (Met or M) Phenylalanine (Phe or F) Trypotphan (Trp or W) Proline (Pro or P) Polar Serine (Ser or S) Threonine (Thr or T) Cysteine (Cys or C) Tyrosine (Tyr or Y) Asparagine (Asn or N) Glutamine (Gln or Q) Acidic Electrically charged Basic Aspartic acid (Asp or D) Glutamic acid (Glu or E) Lysine (Lys or K) Arginine (Arg or R) Histidine (His or H)

40 Fig. 5-17a Nonpolar Glycine (Gly or G) Alanine (Ala or A) Valine (Val or V) Leucine (Leu or L) Isoleucine (Ile or Ι) Methionine (Met or M) Phenylalanine (Phe or F) Tryptophan (Trp or W) Proline (Pro or P)

41 Fig. 5-17b Polar Serine (Ser or S) Threonine (Thr or T) Cysteine (Cys or C) Tyrosine (Tyr or Y) Asparagine (Asn or N) Glutamine (Gln or Q)

42 Fig. 5-17c Acidic Electrically charged Basic Aspartic acid (Asp or D) Glutamic acid (Glu or E) Lysine (Lys or K) Arginine (Arg or R) Histidine (His or H)