Case 2 LOs Flashcards
Outline the relationship between the structural and functional organization of the human body, from molecules to organ systems
The levels of structural organization explain how the big picture of the human body is built from the smallest level to the big picture. The simplest level is known as the chemical level where atoms comprise molecules in the body. These molecules form organelles that inhibit cells at the cellular level. Cells are the smallest unit of life and several of these with the same function can form to create tissue at the tissue level, multiple tissues make organs which we find at the organ level and multiple organs work together to form organ systems at the organ system level. The highest level is the organism itself at the organismal level.
Explain why the cell is considered the functional unit of life
Due to the three tenets of cell theory- all cells must come from pre-existing cells, the cell is the basic building block of life, every living thing is composed of one or more cells. Additionally, they contain the organelles responsible for facilitating the functions of life (MMMR SHENG- Maintaining boundaries (cell wall), movement (flagella), metabolism (mitochondria), Reproduction (DNA/gametes), Sensitivity, Homeostasis, Excretion, Nutrition, Growth). Furthermore, they house genetic material responsible for carrying on life etc.
Identify the major classes of macromolecules and briefly explain their subunit structure and major functions as structural and functional components of cells
Macromolecules are large highly organized molecules (most are polymers), made up of discrete building blocks (or monomers) that are chemically bonded.
The main 4 classes are:
Protein: Carry out many functions; structural proteins (keratin, collagen, cytoskeleton), functional transport (haemoglobin), enzymes (catalysts), defence (immunoglobulin), motor proteins (myosin), storage (Casein), signaling (Hormones), receptors (HGH receptor), gene regulation (transcription factors).
Structure of protein- (Monomer- amino acid, polymer- poly peptide chain, cellular structure- intermediate filament)
Carbohydrates:
Energy store in body, structure (gives tissues shape/strength), cell to cell recognition (allow cells to recognize each other and immune system to recognize foreigners)- (Monosaccharide- starch/polysaccharide- starch grain in a chloroplast)
Nucleotides: Nucleotide, DNA strand, chromosome
Lipids: Diverse group of molecules that are hydrophobic and insoluble; can be triglycerides stored for energy, phospholipids found in membranes, steroids e.g cholesterol & some hormones/vitamins, eicosanoids prostaglandins which have a role in many body functions.
Fats are composed of fatty acids (which can be saturated with no double bonds or unsaturated with one or more double bonds) the polymer is the -fat molecule- adipose cells with fat droplets
Describe the structure and major functions of the organelles found in human cells
Cytoplasmic organelles – metabolic machinery of the cell
Membranous (Nucleus, mitochondria, peroxisomes, lysosomes, endoplasmic reticulum, and golgi apparatus)
Nonmembranous (cytoskeleton, centrioles, and ribosomes)
Nucleus- stores genetic material
Mitochondia- ‘power plant’ of cell, providing its ATP supply
Ribosome- site of protein synthesis (there are freee ribosomes floating in cytosol and membrane bound ribosomes that attach to membranes to make RER- from which they make proteins to export, go to cell wall or lysosomes)
Peroxisomes- contains a lot of enzymes most importantly they neutralize free radicals due to their components of oxidases
Lysosomes- ‘demolition crew’ digest particles taken in by endocytosis, particularly ingested bacteria/viruses/toxins, contain a lot of digestive enzymes
ER (RER produces all proteins secreted from cell, SER produces enzymes super important for many things including LIPIDS, DETOXIFYING DRUGS.
Golgi Apparatus- ‘traffic cop’ modifies, concentrates and packages proteins/lipids.
Nonmembranous organelles=
Cytoskeleton: ‘cells bones, muscles and ligaments’ three rods (microfilaments, intermediate filaments and micro tubules)
Centrioles: The centrosome contains the centrioles which develop spindle fibres for cell division. They also contain microtubules and form the basis of cilia and flagella.
Ribosomes: the ribosomes that float around the cytosol are not membrane bound, only those that attach to the ER are membrane bound.
Outline the role of stem cells and their significance with respect to the diversity of cells in the human body
Unspecialised cells that can specialize into certain cells (unipotent, multipotent, pluripotent, totipotent).
Stem cells are like ‘blank’ cells with the capacity to specialize. Embryo is known as (blastocyst). For example in the epidermis we find stem cells just at the bottom layer at the basal lamina.
Describe the diversity of cells in the human body, providing examples of specific cells and their broad primary functions
Cells in the human body are diverse and specific to their function in order to maximize efficiency.
The human body contains many cells such as endocrine, stem, “sex” (ova/sperm), skeletal muscle, smooth muscle, epidermis.
For example skeletal muscle contains a lot of mitochondrion due to the need for a lot of energy. A sperm cell is the only human cell which has a ‘flagella’ and this is for increased mobility.
Explain why water is the universal solvent
Because water is a Polar Molecule.
The way it is structured it has negative charge on the outside which means it surrounds and then attracts the positive ions of solute molecules. In more detail, it is the unequal sharing of electrons between oxygen and hydrogen that causes this charge.
Due to the hydrogen bonds water has special properties such as surface tension, ability to cool the body, ability to dissolve other polar molecules.
Water is also able to form layers called hydration layers around large charged molecules such as proteins and it acts as the main transport medium as it is such an excellent solvent (e.g waste products are excreted with water through Urine).
Forms lattice network
Makes them interact with each other and thus soluable
Hydrogen bonds are super important not as strong as covalent but there are many
Gives unique properties e.g surface tension
Identify the two broad categories of cells that form or inhabit the human body (eukaryotes and prokaryotes) and briefly describe the key differences between these two broad categories of cells
Eukaryotes are the cells that compose the human body, unlike prokaryotes (that are cells largely comprising bacteria and viruses), Eukaryotes have clearly defined nuclei. Eukaryotes are larger, contain a double strand of DNA, reproduce sexually and have endoplasmic reticulum whereas this is absent in the prokaryotes, which are also smaller and have one circular chromosome of DNA.
