Chapter 7 Flashcards
What is growth?
-depends on the use of DNA to make the structural and functional proteins needed for survival
What is reproduction?
-ensures that genetic information is passed from one generation to the next
Why does protein synthesis matter?
-required for cell growth and maintenance
What is DNA?
-all the instructions for the cell
What is a gene?
-a segment of a DNA molecule that contains the code for synthesizing one RNA molecule
Why does DNA matter for protein synthesis?
-it contains the instructions for how to make the proteins
What is RNA?
-phosphate group, ribose sugar, nitrogenous base
Why does RNA matter for protein synthesis?
- codes the genes
- makes ribosomes
- delivers amino acids to the ribosomes
What kinds of RNA are there and what do they do?
- mRNA: codes the genes
- rRNA: makes ribosomes
- tRNA: delivers amino acids to the ribosomes
What is transcription?
-transcribes a portion of the DNA code
What is translation?
-the new RNA is broken down into three nitrogenous bases (codons) and read as specific amino acids thus creating the bases for proteins
How is the mRNA transcript edited?
-uses uracil instead of a thymine
What are introns and extons?
- introns: noncoding regions; removed; sections of mRNA that aren’t needed
- extons: coding regions; sections of mRNA that are spliced together
What organelle is involved with translation?
-ribosome
How does translation occur?
-the new RNA goes into the ribosome where a polypeptide chain breaks into single pieces and bonds with anticodons to make amino acids
What is the anticodon?
-three bases that exactly complement one mRNA codon
What is posttranslational processing?
-proteins are folded into secondary, tertiary, and quaternary protein molecules
What organelles are involved with posttranslational processing?
- golgi body
- rough ER
- chaperone proteins
What occurs in the G1 and G2 phase?
- cell material is made
- creates more structural proteins and enzymes
- growth and replication of organelles
- growth of plasma membrane
What occurs during the S phase?
- replication of the genome prepares the cell for reproduction
- DNA uncoils and strands unzip
- creates two chromatids
What is a chromatid?
-each of the two threadlike structures that a chromosome divides into
What is a centromere?
-holds the two chromatids together
What is the M phase?
- cells reproduce by splitting themselves into two daughter cells
- cytokinesis
- mitosis
What is cytokinesis?
-splitting of the plasma membrane and cytoplasm into two
What is mitosis?
-the process of organizing and distributing nuclear DNA during cell division
What are the four phases of mitosis?
- Prophase
- Metaphase
- Anaphase
- Telophase
What occurs in the prophase?
- nuclear envelope falls apart
- chromatids coil to form compact chromosomes
- centromeres move towards opposite ends of the cell
What occurs in the metaphase?
- chromosomes are moved into the equator of the cell
- spindle fibers attach to chromatids
What occurs in anaphase?
- each chromosome is pulled away from the middle and to the nearest pole by a spindle fiber
- cytokinesis begins
What occurs in telophase?
- end phase
- nuclear envelope rebuilds
- spindle fibers disappear
- cytokinesis completes
What is meiosis?
- cell division that results in 4 daughter cells instead of two
- contain half the number of chromosomes
- sex cells
What is a diploid cell?
- a cell containing homologous pairs of chromosomes
- 46
What is a haploid cell?
- a cell containing a single set of chromosomes
- 23
What regulates the cell life cycle?
- cyclins control CDKs
- CDKs drive the cell through each phase
