Chapters 2 & 3 Flashcards
Of the 4 major types of biological molecules, which type may be a transporter, enzyme, signaling molecule, or receptor?
Proteins
Of the 4 major types of biological molecules, which type may be a signaling molecule but is never a receptor or enzyme?
Nucleic Acid???
What are the 4 major types of biological molecules?
- Lipids
- Carbohydrates (sugars)
- Nucleic Acids
- Proteins
Describe the structure of glycogen.
A branching chain of glucose molecules.
What are the general characteristics of lipids?
- Biomolecules made of mostly C and H
- Do not interact well with water or charged/partially charged molecules (hydrophobic)
- Do interact well with other lipids
- Used for stored energy (to make ATP from)
Describe the structure of a triglyceride.
3 fatty acids and 1 glycerol
Describe the structure of a steroid.
Molecules with four linked carbon rings
Describe the general structure of a carbohydrate.
Carbon with water
List the specific molecules of the body that are used specifically for storing energy (calories)
triglycerides
Which body cells are especially good at storing glycogen?
Liver cells
If a cell’s membrane were made entirely of phospholipids what sorts of molecules could enter or leave the cell?
Oxygen, Carbon dioxide, and lipids (steroids)
List an organ where simple squamous epithelium is common. Describe where in that organ it is found. What is the function.
It lines the bowmans capsule of the kidney.
Filtration of fluid from capillaries.
List an organ where stratified squamous epithelium is common. Describe where in that organ it is found. What is the function.
In the lining of the esophagus.
Protection from friction.
List an organ where simple cuboidal epithelium is common. Describe where in that organ it is found. What is the function.
In the PCT (proximal convoluted tubule) of the kidney.
Re-absorption of water in the kidney.
List an organ where pseudostratified ciliated columnar epithelium is common. Describe where in that organ it is found. What is the function.
In the lining of the trachea.
secretion of mucus to trap particles.
List an organ where transitional epithelium is common. Describe where in that organ it is found. What is the function.
In the lining of the bladder.
Specialized for distention.
List an organ where loose areolar CT is common. Describe where in that organ it is found. What is the function.
underneath all epithelia.
wraps and cushions organs
List an organ where adipose CT is common. Describe where in that organ it is found. What is the function.
hyperdermis.
storing triglycerides for energy
List an organ where hyaline cartilage is common. Describe where in that organ it is found. What is the function.
Makes up the costal cartilage of the rib
resists compression when one bone is pushing against another.
List an organ where bone CT is common. Describe where in that organ it is found. What is the function.
in bones
calcium storage
Normal human body cells have how many chromosomes?
46
What are the four phases of mitosis?
Prophase, Metaphase, Anaphase, Telophase
What happens in Prophase?
Chromosomes condense and become visible, spindle fibers attach to centromeres, and pull chromosomes in opposite directions. The nuclear membrane and nucleolus disappear.
What happens in Metaphase?
Chromosomes align along metaphase plate.
What happens in Anaphase?
Centromeres split and chromatids are pulled to opposite ends of cell.
What happens in Telophase?
Each chromatid is now a chromosome. New nuclear envelope forms, spindle disassembles. Division of the cytoplasm.
If you could make visible a chromosome in G1 of the cell cycle what would it look like?
The chromosomes are in an extended form and seen as chromatin, the nucleus is visible.
What are the phases of interphase of the cell cycle and what is happening during each phase?
G1 - the cell grows
S Phase - the cell makes copies of its chromosomes. Each chromosome now consists of two sister chromatids.
G2 - the cell checks its duplicated chromosomes and gets ready to divide
A picture of a persons chromosomes is called a what?
karyotype
Describe the primary structure of a protein.
linear sequence of amino acids
How many different amino acids are there?
20
Describe the secondary of a protein.
Alpha helix (coil) or a beta sheet (folded)
Describe the tertiary structure of a protein.
a combo of alpha helix and beta sheets
Describe the quaternary structure of a protein.
a protein consisting of more than one amino acid chain
The molecule that almost always donates needed energy directly to a process in a cell that requires energy is what?
ATP
Describe the basic structure of a nucleotide.
phosphate - sugar - base
Describe the basic structure of DNA
Double stranded molecule (DNA is made up of six smaller molecules – a five carbon sugar called deoxyribose, a phosphate molecule and four different nitrogenous bases (adenine, thymine, cytosine and guanine).
List the 4 bases found in DNA and indicate which pair with which.
Adenine, Thymine, Guanine, and Cytosine
Adenine pairs with Thymine
Guanine pairs with Cytosine
List the 4 bases in RNA
Adenine, Guanine, Cytosine and Uracil
With respect to the functional compartmentalization of the body, what are the two large fluid-filled spaces and what is the total percent of total body fluid that is in each?
Extracellular Fluid 1/3 and Intracellular Fluid 2/3
List the two major sub-compartments of extracellular fluid. About how much ECF do they each contain?
Blood plasma 25% and interstitial fluid 75%
Describe the structure of the plasma membrane (be sure to name the molecules and their arrangement). About how much of each type of molecule contributes to the PM?
50% lipid (phosphate head group with 2 fatty acid tails)
50% protein
In addition to forming the out limit of the cell, what role does the lipid component play in the function of a plasma membrane?
It creates a hydrophobic layer which is a barrier to almost all molecules except for O2, CO2, lipids (steroids)
What is an organelle? Describe the structure of an organelle. Describe its function.
Organelles “little organs” are membrane bound compartments that play specific roles in the overall function of the cell.
Structure: subcellular compartments separated from the cytosol by one or more phospholipid membranes similar in structure to the cell membrane (membranous)
- ribosomoes - read messenger RNA to produce the primary structure of a protein.
- mitochondria - produces energy and ATP
- Endoplasmic reticulum - synthesis, storage, and transport of biomolecules
- Golgi Apparatus - receives proteins made on the rough ER, modifies them, and packages them into the vesicles.
What is an Inclusion? Describe the structure of an inclusion. Describe its function.
Inclusions are particles of insoluble materials.
Structure: no boundary membranes so they are indirect contact with the cytosol.
Function: store nutrients as glycogen granules and lipid droplets
1. Liver - releases glucose
2. skeletal muscle cells
3. lipid droplet
Prophase 1 of Meiosis has some important differences compared to mitosis. Describe the major differences.
In Meiosis homologous chromosomes pair up and form tetrads and then crossover occurs, in Mitosis the tetrads are already formed and spindle fibers attach to their centromeres.
What happens in Prophase 1 of meiosis?
Homologous chromosomes pair up and chromatids form tetrads (synapsis). Crossover occurs, which mixes gene combinations.
What happens in Metaphase 1 of meiosis?
Homologs align one on either side of metaphase plate. Non-homologous chromosomes assort independently.
What happens in Anaphase 1 of meiosis?
Homologous are pulled to opposite ends of the cell, halving the chromosome number.
What happens in Telophase 1 of meiosis?
2 genetically distinct haploid (n) cells formed.
In Meiosis 2 what happens during prophase 2, Metaphase 2, and Anaphase 2?
Basically the same thing as in mitosis.
Metaphase 1 of meiosis has some important differences compared to mitosis. Describe the major differences.
In meiosis tetrad pairs line up along the metaphase plate, one on either side and in mitosis single tetrads line up along the metaphase plate.
Anaphase 1 of meiosis has some important differences compared to mitosis. Describe the major differences.
In meiosis the tetrad pairs are pulled to opposite ends of the cell halving the chromosome number and in mitosis the tetrads split at the centromeres and the chromatids are pulled to the opposite end of the cell.
How many chromosomes are present in a sperm after meisosis is complete?
23
A man and woman are both heterozygous for cystic fibrosis (an autosomal recessive disease). What is the probability of producing a child with cystic fibrosis? What is the probability of producing a child who is a carrier?
25% of producing a child with it.
50% of the child being a carrier
Describe the molecular structure of a gene. What is a gene?
Gene - a functional unit of DNA that codes for the production of specific polypeptide or a specific protein. The protein thus produced in turn causes a particular trait.
Molecular structure: The vast majority of living organisms encode their genes in long strands of DNA (deoxyribonucleic acid). DNA consists of a chain made from four types of nucleotide subunits, each composed of: a five-carbon sugar (2’-deoxyribose), a phosphate group, and one of the four bases adenine, cytosine, guanine, and thymine.
What is a metabolic pathway?
A series of chemical reactions occurring within a cell.
These reactions are catalyzed by enzymes, where the product of one enzyme acts as the substrate for the next.
Define Inborn errors of metabolism.
inheritable gene defects that affect the metabolism of macromolecules, most often simply because the lack of a single enzyme.
Explain how genes are involved in metabolic pathways.
In Inborn Errors of Metabolism a defective gene that codes for a specific enzyme can affect the final product of the reaction. (i.e. producing no final product, too much of it, or an too much of an intermediate product.)
People who are carriers of autosomal recessive diseases show no symptoms of the disease. How can this be? Provide a molecular explanation as to why this is?
They are carriers because they are heterozygous (possessing one dominant and one recessive of the gene). Since the disease lies in the recessive gene it is shadowed by the dominant gene.
A woman who carries the normal gene for red-green color vision (and is not a carrier) has children with a red-green colorblind man. Red green color blindness is a sex linked trait. What would my punnett square look like?What % of sons will be color blind? What % of daughters will be color blind? What percent of each will be carriers?
Woman - XAXA
Man - XaY
Neither their sons or daughters will be colorblind.
100% chance of their daughters being carriers
0% chance of their sons being carriers
What is the composition, structure, and function of lipids?
Biomolecules made mostly of carbon and hydrogen.
1 glycerol and 3 fatty acids.
nonpolar and not water soluble.
function: used for stored energy (to make ATP from)
What is the composition, structure, and function of carbohydrates?
Biomolecule made of carbon and water. (General formula is CH2O) “sugars”
Function:
Providing energy and regulation of blood glucose
Sparing the use of proteins for energy
Breakdown of fatty acids and preventing ketosis
Biological recognition processes
What is the molecular formula for glucose?
C6H12O6
What is the composition, structure, and function of nucleotides and nucleic acids?
Nucleotide consists of one or more phsophate groups, a 5-carbon sugar, and a carbon-nitrogen ring structure nitrogenous base. Nucleic acid - a chain of nucleotides Function: energy capure and transfer cell-to-cell communication
What is the composition, structure, and function of proteins?
"amino acids" - carboxyl group (-COOH), an amino group (-NH2), and a hydrogen attached to the same carbon. The fourth bond of the carbon attaches to a variable "R" group. Function: Repair and Maintenance Energy Hormones Enzymes Transportation and storage of molecules Antibodies
What are the four important biological roles of electrons.
- covalent
- ionic bonds
- energy capture and transfer
- formation of free radicals
Review and compare the different types of covalent and noncovalent bonds.
Covalent bonds - result when atoms share electrons. These bonds require the most energy to make or break. 1. nonpolar molecules 2. polar molecules Noncovalent bonds 1. Ionic bonds 2. hydrogen bonds 3. Van der Waals Forces
What is solubility?
the degree to which a molecule is able to dissolve in a solvent
Define hydrophilic.
Molecules that are soluble in water are said to be hydrophilic.
Define hydrophobic.
Molecules that do not dissolve well in water.
What is pH?
the concentration of free H+ in body fluids, or acidity, is measured in terms of pH
What is an acid?
a molecule that contributes H+ to a solution.
What is a base?
a molecule that decreases the H+ concentration of a solution by combining with free H+.
List seven important functions of soluble proteins in the body.
- Enzymes
- Membrane transporters
- Signal molecules
- Receptors
- Binding proteins
- Immunoglobulins
- Regulatory proteins
Explain the meanings of affinity, specificity, saturation, and competition in protein-ligand binding.
Affinity - the degree to which a protein is attracted to a ligand (any molecule or ion that binds to another molecule)
Specificity - the ability of a protein to bind to a certain ligand or a group of related ligands.
Saturation - the total number of binding sites that are occupied by ligands per unit time.
Competition - the related ligands that compete for the binding sites
Explain the different methods by which modulators alter protein binding or protein activity.
Competitive inhibitor - Competes directly with ligand by binding reversibly to active site
Irreversible inhibitor - binds to binding site and cannot be displaced
Allosteric modulator - binds to protein away from binding site and changes activity; may be inhibitors or activators
Covalent Modulator - binds covalently to protein and changes its activity.
pH and Temperature - Alter three-dimensional shape of protein by disrupting hydrogen or S-S bonds; may be irreversible if protein becomes denatured.
Name and describe the major body cavities and compartments. Explain the
four major functions of the cell membrane.
Cavities
1. Cranial cavity
2. Thoracic cavity
3. Abdominopelvic cavity
Functional Compartments
1. Intracellular Fluid (ICF)
2. Extracellular Fluid (ECF) which is divided up into plasma and interstitial fluid
Cell Membrane
1. Physical isolation - Seperates the cell from the ECF
2. Regulation of exchange with the environment
3. Communication between the cell and its environment
4. Structural support
Compare a phospholipid bilayer to a micelle and a liposome.
Phospholipid bilayer - forms a sheet
Micelles - droplets of phospholipids
Liposomes - have an aqueous center
What’s inside the cell membrane?
- Cytolsol - watery fluid of the cytoplasm
- Inclusions - gylcogen granules (lots of glucose)
Liver, skeletal muscle cells, lipid droplet - Organelles - “little organs” are membrane bound compartments that play specific roles in the overall function of the cell.
Ribosomes, mitochondria, ER, Golgi - Protein fibers
- Nucleus - “control center”
Describe the organization and function of the nucleus.
The nucleolus is surrounded by a double-membrane nuclear envelope which is pierced by pores to allow communication with the cytoplasm.
Function: “control center” produce RNA (mRNA codes for protein, rRNA in ribosomes, tRNA transfers amino acids)
Explain how protein synthesis uses compartmentalization in the cell to separate different steps of the process.
- mRNA is transcribe from genes in the DNA
- mRNA leaves the nucleus and attaches to cytosolic ribosomes, initiating protein synthesis
- Some proteins are released by free ribosomes into the cytosol or are targeted to specific organelles.
- Ribosomes attached to the rough ER direct proteins destined for packaging into the lumen of the rough ER.
- Proteins are modified as they pass through the lumen of the ER.
- Transport vesicles move the proteins from the ER to the Golgi apparatus
- Golgi cisternae migrate toward the cell membrane.
- Some vesicles bud off the cisterane and move in a retrograde or backward fashion.
- some vesicles bud off to form lysosomes or storage vesicles
- other vesicles become secretory vesicles that release their contents outside the cell.
What is the extracellular matrix?
extracellular material that is synthesized and secreted by the cells of a tissue.
Describe the role of proteins in the three major categories of cell junctions
- Gap junctions - proteins interlock to create passageways that look like hollow rivets with narrow channels through their centers.
- Tight junctions - proteins help fuse together the cell membranes of adjacent cells making a barrier
- Anchoring junctions - membrane proteins connect the cells together across the intercellular space. (like a zipper)
Explain the differences between apoptosis and necrosis.
Apoptosis - programmed cell death
Necrosis - cells die from physical trauma, toxins, or lack of oxygen when their blood supply is cut off.
