PSL201Y1 Study Guide - Summer 2018, Comprehensive Midterm Notes - Robert E. Lee, Ion, Gastrointestinal Tract
PSL201Y1
MIDTERM EXAM
STUDY GUIDE
Fall 2018
Kristyn Lee
1
PSL201Y
BASIC HUMAN PHYSIOLOGY
TOPIC: INTRODUCTION TO PHYSIOLOGY AND CELL TRANSPORT
Parts of a Cell
Plasma Membrane
- Phospholipids are arranged in a bilayer
- Hydrophilic head face the cytosol and the extracellular fluid
- Hydrophobic tails face each other
- Cholesterol molecules interfere with hydrophobic interactions between
phospholipid tails
- Causes crystallization of the bilayer thereby decreasing its fluidity
- Membrane proteins are dispersed throughout the bilayer
- Integral membrane proteins maintain contact with both the lipid bilayer and the
aqueous environment
- Transmembrane proteins span the lipid bilayer (e.g. ion channels)
- Others are located only on one side (e.g. G proteins)
- Peripheral membrane proteins are located on the cytosolic surface
- Can be dissociated from membrane and leave it intact
- Membrane carbohydrates covalently bond to membrane lipids or proteins
- With lipids, they form glycolipids
- With proteins, they form glycoproteins
- Function as a protective layer (glycocalyx) that holds cells together and aids in
cell recognition and cell labelling
Nucleus
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Kristyn Lee
2
- Nuclei contain genetic material of the cell, DNA
- DNA exists as thin threads called chromatin
- Surrounded by nuclear envelope
- Consists of two membranes that fuse intermittently
- Leaves nucleus pores that allow selective movement of molecules
- Nucleolus is within the nucleus and serves as the site of synthesis of rRNA
Cytosol
- Gel-like structure that contains enzymes that catalyse specific chemical reactions
- Stores energy in the form of triglycerides or glycogen in masses called inclusions
Endoplasmic Reticulum
- Rough endoplasmic reticulum are flattened sacs with attached ribosomes
- Associated with the synthesis of proteins destined for the plasma membrane or
another organelle
- Smooth endoplasmic reticulum consists of tubules with no ribosomes attached
- Site of the synthesis of lipids (triglycerides and steroids)
- Site of storage of calcium ions
Golgi Apparatus
- Consists of membrane-bound flattened sacs called cisternae
- Closely associated with the endoplasmic reticulum on cis-face
- Other side faces plasma membrane = trans face
- Processes molecules synthesized in the endoplasmic reticulum and packages them into
vesicles
Mitochondria
- Bound by two membranes, thus dividing the organelle into two compartments
- Intermembrane space (between membranes)
- Mitochondrial matrix (innermost compartment)
- Inner mitochondrial membrane houses the electron transport chain
- Folded into tubules called cristae to increase surface area
- Most of the cell’s usable energy form, ATP, is produced
Lysosomes
- Contains enzymes that degrade intracellular debris and extracellular debris
- Can be engulfed in the process of endocytosis
Peroxisomes
- Structures similar to lysosomes
- Contain more than 50 enzymes that carry out oxidation and thereby degradation
- Most abundant in the liver and kidney cells
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Document Summary
Hydrophilic head face the cytosol and the extracellular fluid. Cholesterol molecules interfere with hydrophobic interactions between phospholipid tails. Causes crystallization of the bilayer thereby decreasing its fluidity. Membrane proteins are dispersed throughout the bilayer. Integral membrane proteins maintain contact with both the lipid bilayer and the aqueous environment. Transmembrane proteins span the lipid bilayer (e. g. ion channels) Others are located only on one side (e. g. g proteins) Peripheral membrane proteins are located on the cytosolic surface. Can be dissociated from membrane and leave it intact. Membrane carbohydrates covalently bond to membrane lipids or proteins. Function as a protective layer (glycocalyx) that holds cells together and aids in cell recognition and cell labelling. Nuclei contain genetic material of the cell, dna. Dna exists as thin threads called chromatin. Consists of two membranes that fuse intermittently. Leaves nucleus pores that allow selective movement of molecules. Nucleolus is within the nucleus and serves as the site of synthesis of rrna.
