Mid term focused questions Flashcards
Is a pH of 10 acidic or basic?
Basic.
Is a pH of 3 acidic or basic?
Acidic.
What are 2 differences between DNA and RNA?
RNA has uracil and DNA has thymine, DNA is a two stranded double helix and RNA is single stranded.
Describe a proton.
Positively charged, in the nucleus. Have an atomic mass of 1. Atomic mass refers to protons.
Describe an electron.
Negatively charged, away from the nucleus in the shell. Capture and release energy.
Describe a neutron.
No charge, in the nucleus. Have an atomic mass of 1. Isotopes refer to neutrons.
Describe carbohydrates.
Quick fuel and short energy storage, Monomers that are one molecule are called monosaccharides, usually 3-7 carbons in size.
Describe proteins.
They are polymers made up of amino acid monomers. Lots of different types like; enzymes, hemoglobin, actin in muscles, hormones, antibodies.
Describe lipids.
Contain most energy of biological molecules, they are hydrophobic. Different forms can be: fats, oils, phospholipids and steroids.
Describe nucleic acids.
DNA, RNA, nucleotides are the monomers of DNA and RNA. DNA nucleotide specifically is: the sugar deoxyribose, phosphate group and nitrogenous base. RNA nucleotide specifically is: A ribose sugar, phosphate group and nitrogenous bases.
What links peptide bonds?
Proteins.
Describe an enzyme.
Typically proteins that function as catalysts to speed up chemical reactions. They don’t get used up and can be used multiple times.
When do hydrogen bonds occur?
Between nitrogenous bases in DNA.
When does dehydration synthesis occur?
Joining of two molecules together, by removing water.
When does hydrolysis occur?
Breaking of molecules in waters like acids, bases, and salts.
Describe isotonic solution.
The solute concentration is equal inside and outside of the cell.
Describe hypertonic solution.
A solution has a higher solute concentration than the inside of the cell.
Describe hypotonic solution.
A solution has a lower solute concentration than the inside of the cell.
Are humans prokaryotes or eukaryotes?
Eukaryotes.
Describe the difference between prokaryotes and eukaryotes.
Prokaryotes lack membrane bound organelles, and eukaryotic cells have membrane bound organelles.
What are all the ways things can move in and out of the cell?
Diffusion, facilitated transport, active transport, exocytosis, and endocytosis.
Which passage of molecules into and out of the cell do NOT require energy?
Diffusion, facilitated transport.
What passage of molecules into and out of the cell do require energy?
Active transport, exocytosis, endocytosis.
Describe grana and stroma.
Belongs to plant cells; grana are stacks of thylakoids, stroma is the fluid filled space bounded by double membranes.
What are the types of endergonic reactions? (Endocytosis).
Phagocytosis, Pinocytosis, and receptor mediated endocytosis.
Explain Phagocytosis.
Large, particulate matter such as “food” molecules, viruses or whole cells.
Explain Pinocytosis.
Liquids and small particles dissolved in liquid.
Explain receptor mediated endocytosis.
A type of pinocytosis that involves a coated pit.
What stage of respiration has FAD becoming FADH2?
Citric acid cycle.
At what stage does a two carbon sized molecule link with coenzyme A and become Acetyl-CoA?
Preparatory stage.
What stage will NADH + H+ will become oxidized to NAD?
Electron transport chain.
By far, the most ATP generated occurs at what stage?
Electron transport chain.
At what stage does a 2 carbon sized molecule join with a four carbon molecule. The two carbon molecules get used up as CO2 and NADH is made.
Citric acid cycle.
What stage do all carbons from the original glucose molecule are now gone?
Electron transport chain.
During what stage is there a buildup of H+ in the intermembrane space?
Electron transport chain.
The anaerobic process of cell respiration can occur after this stage is completed.
Glycolysis.
What stage are electrons going to a lower energy level?
Electron transport chain.
What are the 4 phases of cellular respiration?
Glycolysis, preparatory reaction, citric acid cycle, electron transport chain.
Describe glycolysis.
Breakdown of glucose into 2 molecules of pyruvate, causes removal of electrons and H+ and provides energy for 2 ATP. Break down 6 glucose into: 2 G3P molecules, cost of 2 ATP to ADP. G3P molecules have a phosphate group attached.
Describe Preparatory reaction.
Pyruvates move into cristae of mitochondria, each pyruvate reacts and links to a coenzyme A molecule. During this, each pyruvate loses a CO2 molecule. Occurs twice, two NADH molecules are made.
Describe Citric acid cycle.
Cyclical series of oxidation reactions that produce one ATP and carbon dioxide per turn. Each cirtic acid loses two carbons, get an ATP and FADH2 and 3 NADH.
Describe electron transport chain.
Series of electron carrier . Occurs in the cristae of mitochondria. All of the NADH produced at glycolysis, prep reaction, and citric acid cycle. FADH2 becomes FAD, NADH becomes NAD+.
Describe free energy.
The amount of energy available to do work.
Describe activation energy.
Energy that must be adde to cause reactants to react with each other. (Such as you need a match to start wood burning).
What is a redox reaction?
Chemical reaction that involves the transfer of electrons (loss or gain).
What is a coupled reaction?
When the energy released from an exergonic reaction is used to fuel an endergonic reaction.
What are the functions of the lymphatic system?
Returning excess tissue fluid to the bloodstream
Absorbing fats from the digestive system and transporting them to the bloodstream
Defending the body against disease.
What forms a one way system that begins with lymphatic capillaries?
Lymphatic vessels.
What are small close ended vessels with thin walls?
Lymphatic capillaries.
What do lymphatic capillaries do?
Absorb excess tissue fluid, return fluid inside called lymph to the bloodstream.
What is edema?
Localized swelling caused by accumulation of fluids in the tissues. Too much fluid is being produced and not enough is being drained.
Where does lymph enter the body?
Thoracic duct.
What are some primary lymphoid organs?
Thymus, red bone marrow
What are some secondary lymphoid organs?
Spleen, lymph nodes.
What is the mitotic stage?
When the cell undergoes division.
What is mitosis?
Division of the nucleus.
What is cytokinesis?
Division of the cytoplasm.
Describe prophase.
Nuclear membrane disappears, centrosomes migrate, spindle fibres appear. Chromatin condenses and chromosomes become visible. Chromosomes have no particular orientation.
Describe prometaphase.
Centromeres attach to spindle fibres, centrosomes migrate to either end.
Describe metaphase.
Spindle fully forms and consists of poles, asters and fibres. Chromosomes line up at metaphase plate.
Describe anaphase.
Centromeres divide and sister chromatids are moved to opposite poles by fibres.
Describe telophase.
Nuclear membrane reforms, spindle disappears, cytokinesis occurs, chromosomes become more diffuse again. Nucleolus appears in each daughter nucleus.
What stage does crossing over occur?
Prophase 1.
Describe a dominant allele.
Represented by a capital letter, the allele that masks the expression of the alternate allele when both are present in an organism.
Describe a recessive allele.
Represented by a lowercase letter, over-rode by dominant allele.
Describe incomplete dominance.
Occurs when the heterozygote has an intermediate phenotype between the two homozygotes. (Curly haired and straight haired person will have a wavy haired child).
Describe co-dominance.
Occurs when alleles are equally expressed in a heterozygote. (Chickens with both white and black feathers).
What does the immune system do?
Protects body from pathogens, toxins and threats.
What are the two types of immunity?
Adaptive and innate.
Describe the differences between adaptive and innate immunity.
Innate immunity: able to fight threats without without previous exposure.
Adaptive immunity: initiated from previous exposure.
What does innate immunity use?
Barriers, inflammatory response, and cell types.
What is a physical barrier?
Skin, mucus coverings.
What is a chemical barrier?
Sweat, stomach acid.
What do dendritic cells do?
Release cytokines to signal other cells to act.
What do neutrophils do?
A macrophage that releases pus.
What is an interferon?
Proteins produced by cells that have been infected by viruses. They bind to receptors of non-infected cells. Stop viral replication.
What do antigens have to do with? Innate or adaptive?
Adaptive.
What do B and T cells do and how are they related?
B cells make the Y shaped antibodies that recognize and bind to antigen surface. T cells help B cells make antibodies and inactivate pathogen.
What is active immunity?
Person alone produces immune response.
What is passive immunity?
Person received antibodies or cells from another individual.
Describe spermatogenesis.
Occurs in the testes of males.
Start with primary spermatocyte, Meiosis 1 occurs, results in 2 secondary spermatocytes. Meiosis 2 occurs and you end up with 4 spermatids which then mature into sperm.
Describe oogenesis.
Begins in the fetus, then resumes at puberty and occurs every menstrual cycle.
Start with primary oocyte, divides in meiosis 1 to produce one secondary oocyte and one polar body. If secondary oocyte is fertilized, meiosis 2 will occur. Second polar body can form, but if not fertilized, secondary oocyte will disintegrate.
What is apoptosis?
Programmed cell death, decreases number of cells that have aged and no longer function well. It is important in the prevention of cancer.
How many rings do purines have?
2.
How many rings do pyrimidines have?
1.
How are nitrogenous bases connected?
Hydrogen bonds.
What does DNA helicase do?
Unzips double stranded DNA.
What does DNA polymerase do?
Fits complementary DNA nucleotides to complimentary bases on loose strands.
What does DNA ligase do?
Seals any breaks in sugar phosphate back bones, ensures new double helix molecules are identical to original.
Describe mRNA.
Produced in the nucleus, section of DNA is used as a template to produce mRNA: transcription.
What is an intron?
Intragene segments.
What is an exon?
RNA nucleotides that remain and will be expressed.
Describe tRNA.
Produced in nucleus, 3 of the nucleotides are the anticodon.
Describe rRNA.
Produced in nucleolus, use section of DNA to make a strand, goes to cytoplasm, combines with proteins and other rRNA molecules.
What is the difference between carrier and channel proteins?
Carrier protein: selectively interacts with specific molecule or ion so that it can cross the plasma membrane.
Channel protein: allows a particular molecule or ion to cross the plasma membrane freely.
Describe crossing over.
Chromatids homologous chromosomes exchange pieces of DNA with each other. Resulting chromosomes have sister chromatids that are no longer identical.
What is oxidation?
Loss of electrons.
What is reduction?
Gain of electrons.
Describe chemiosmosis.
The movement of H+ across a semi permeable membrane instead of water, energy released is used to make ATP.
What is a centromere?
What holds two sister chromosomes together.
What is a chromosome?
Condensed chromatin, holds DNA.
What is a locus?
The location of a gene on a chromosome.
What looks like a clover?
tRNA.
What are mutagens?
Environmental influences that can cause mutations.
What is a transposon?
Jumping genes.
What are the purine bases?
Adenine and Guanine.
What are the pyrimidine bases?
Thymine and Cytosine.
