August 2006 Practice Exam Flashcards
Organelle that packages and stores proteins
Golgi Body
Mitochondria
Deal with respiration and energy production
What type of chemical bond occurs between DNA strands
weak hydrogen bond
DNA is a molecule of what
Nucleotides, nitrogen bases
Characteristics of DNA
Double helix
Thymine
Deoxyribose
Steps of DNA replication
- “unzip” the double helix. helicase breaks down the hydrogen bonds holding the nitrogen bases together
- Replication fork, one strand goes in the 3’-5’ direction and becomes the leading strand, while the other is the lagging strand
- The next processes vary by strand
Steps of DNA replication for the leading strand
RNA Primer binds to DNA strand to act as a starting pont for DNA synthesis
DNA polymerase binds to the DNA strand and adds the complimentary bases
Continuous
Steps of DNA replication for the lagging strand
Numerous RNA primers are made by the primase enzyme and bind at various points along the lagging strand
Chunks of DNA (okazaki fragments) are added in the 5’-3’ direction
Discontinuous (will need to be put together eventually
Protein Synthesis
A succession of tRNA RNA molecules charged with appropriate amino acids and brought together with an mRNA molecule
mRNA
Messanger RNA - Encodes amino acid sequence of a polypeptide
tRNA
Transfer RNA - Brings amino acids to ribosomes during translation
rRNA
Ribosome RNA - with ribosomal proteins, makes up the ribosomes, the organelles that translate mRNA
Integral Proteins
Have specific functions unique to each one of them
Largely determine a membranes specific functions
(Carrier, channel, receptor, enzymatic…)
Peripheral proteins
Often have a structural role as they help stabilize and shape the plasma membrane
Active transport
Movement of molecules across cell membrane from a region of lower concentration to a region of higher concentration
Moves them against their concentration gradient
Uses ATP
Examples of active transport
water moving into cells when they are placed in a hypotonic solution
Osmotic Pressure
The pressure that would have to be applied to a pure solvent to prevent it from passing into a given solution via osmosis
What hormone causes the metabolic rate of body cells to increase
Thyroxin - Causes metabolic rate and body heat production to increase
THYRoid gland controls the release
Where in the digestive track does the breakdown of a substance produce maltose
in the stomach and mouth, made in the pancreas secreted as part of saliva
What is a result of increased secretion by the liver?
An increased concentration of glycerol in the duodenum
Steps of blood clotting
- Platelet plug forms
- Thrombin acts as an emzyme and causes fibrinogen to form long fibrin threads
- Fibrin threads entwine the platelet plug forming a mesh-like frame work for a clot
- This traps the red blood cells, forming a clot
Lymphatic System
The network of vessels through which lymph drains from the tissues into the blood
Part of the circulatory and the immune system
Helps rid the body of toxins and materials
Diastole
Period of isovolumic relaxation
Passive ventricular filling
Systole
Period of isovolumic contraction
Period of ejection
Sinoatrial node
The hearts natural pacemaker
Located in the upper righthand wall of the right atrium
What happens during inhalation
Diaphragm contracts and moves downward which increases the space in your chest cavity
Intercostal muscles between your ribs also enlarge chest cavity as they pull your ribs upward and outward when they CONTRACT
What part of the brain controls inhalation
Medulla oblongata
Brain stem
controls breathing, heart rate, blood pressure and alertness
As carbon dioxide enters the blood during internal respiration, ____ decreases
Water
Medulla Oblongata
Continuation of the spinal cord with the skull, forming the lowest part of the brain stem
Steps of chemical digestion
- Amylase in the saliva works to start the breakdown of carbohydrates
- Gastric juices in the stomach breakdown food into chyme
- In the small intestine, a mix of bile, enzymes and fluids are released. Enzymes break down carbohydrates to their smallest possible pieces
- Large intestine absorbs nutrients as needed
Structure of arteriole
Tiny branches of arteries that lead to capillaries. Constrict and dilate to control blood flow
Strong, thick wall for their size, high percentage of smooth muscle
Changes speed and pressure of blood so when it reaches capillaries it isn’t pulsing.
