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Microbiology
Microbiology -Chapter 3
Question | Answer |
---|---|
bacterial capsules are important in: | survival |
the cell organelles responsible for the packaging of proteins are the: | gogli complexes |
the cell organelles found only in algae and plant cells is the: | chloroplasts |
the intracellular fluid has a high concentration of: | potassium |
an active transport mechanism: | pinocytosis |
the compound that enters the Krebs cycle and combines with oxaloacetic acid is: | Acetyl-CoA |
not found in all bacterial cells" | capsule |
the anticodons are located in: | tRNA |
the phase of mitosis when chromatids separate: | anaphase |
cells without a nucleus are: | prokaryotic cells |
the sterol-like molecules in bacterial plasma membranes are: | hopanoids |
a cell organelle that contains digestive enzymes is a: | lysosome |
the allosteric site is present in: | enzymes |
the organelle necessary for photosynthesis is a: | chloroplast |
Compare and contrast prokaryotic and eukaryotic cells. | Prokaryotic cells: • 70s ribosomes • No nucleus • No membrane-bound organelles • DNA and RNA Eukaryotic cells: • 80s ribosomes • Nucleus • Membrane-bound cell organelles • DNA and RNA |
Describe the cell wall of gram-positive and gram-negative cells. | The cell wall of a gram-positive bacterial cell has a thick peptidoglycan layer external to the plasma membrane and it contains polysaccharides such as teichoic and lipoteichoic acid. The space between the plasma membrane and cell wall—the periplasmic spa |
Discuss the regulation of enzyme activity. | Enzyme activity can be regulated/influenced by a number of factors, such as temperature, pH, substrate concentration, enzyme concentration, product concentration, cofactors, and coenzymes. |
Name and describe the pathways of aerobic cellular respiration. | Aerobic cellular respiration requires three pathways: (1) glycolysis—the breakdown of glucose into two molecules of pyruvic acid (the process occurs in the cytoplasm and produces two molecules of ATP and two molecules of reduced NAD), which is followed by |
Describe the cell cycle and the phases of mitosis. | Eukaryotic cells undergo a sequential series of events between cell division called the cell cycle. This cycle has four phases: G1, S, G2, and mitosis. Mitosis consists of four stages: prophase, metaphase, anaphase, and telophase, followed by the division |
nonchromosomal DNA molecules in bacteria are: | plasmid |
the transfer of genetic material drug cell-to-cell contact is: | conjugation |
Differentiate between genotype and phenotype. | Genotype is the exact genetic makeup of an organism. Phenotype is the observable characteristics or appearance of the organism |
gram-positive bacteria | has a thick peptidoglycan layer (20 to 80 nm) located external to the cell membrane |
gram-negative bacteria | has a thin (5 to 10 nm) peptidoglycan layer that is more complex because it has an outer membrane that provides a cover that is anchored to the lipoprotein molecules of the peptidoglycan layer. |
biofilm | microbial community enclosed by extracellular, mostly polysaccharide polymeric matrix. Biofilms develop when free-floating microorganisms attach to a surface. the first colony initially adheres to a given surface by van der Waals forces. |
diffusion | like other passive transport mechanisms, uses the concentration gradient to move molecules from an area of higher concentration to an area of lower concentration |
binary fission | the form of asexual reproduction by which all bacteria and most protists reproduce |
mitosis | a type of cell division that results in two daughter cells each having the same number and kind of chromosomes as the parent nucleus, typical of ordinary tissue growth. |
meiosis | the reduction of the diploid chromosome number to a haploid state in gametes occurs during reduction division. A single duplication of chromosomes occurs and two cell divisions follow |
cell division | the process by which a parental cell divides into two daughter cells. It is the biological basis for life. |
cellular respiration | the process by which the chemical energy of nutrient molecules is released and captured in the form of ATP |
aerobic cellular respiration | uses oxygen and yields many more ATP molecules than anaerobic cellular respiration, which does not use oxygen and yields only two ATP molecules |
anaerobic cellular respiration | if oxygen is not available ,cellular respiration continues with other inorganic molecules acting as the final electron acceptors |
regulation of enzyme activity | rates at which enzymes reactions proceed within the metabolic pathways are influenced by temperature, pH, concentration of substrate, enzyme, and product; and the presence or absence of cofactors and coenzymes. |
enzymes | biological catalysts that initiate the chemical reactions necessary within the metabolic pathways of cells. All chemical reactions within a cell require enzymes. |
cellular metabolism | includes all chemical reactions within a cell, which are organized in sequence called metabolic pathways |
catabolism | metabolic pathways that break down large molecules into smaller ones and release energy in the process |
anabolism | the pathways that produce larger molecules from smaller ones and use energy released during catabolic reactions |