Chapter 3 Cell Function Flashcards
Protein synthesis consists of?
transcription and translation
Copying the DNA sequence into mRNA is known as what?
Transcription
What is the template for mRNA synthesis?
The sense strand
How does mRNA leave the nucleus?
through nuclear pores
What is translation?
translating the nucleotide sequence of mRNA into a sequence of amino acids forming a protein.
Where does translation occur?
where you find ribosomes: free in the cytosol and upon the outer surface of rough ER
What macromolecule facilitates translation of mRNA into a polypeptide?
Transfer RNA or tRNA
What is a codon?
the amino acid possessed by each tRNA that’s for a specific sequence of 3 mRNA nucleotides that are read together.
How many amino acids coded for by the codons?
20
How are amino acids on adjacent tRNA joined together?
Peptide bonds
Which cells possess a complete set of chromosomes?
All cells with a nucleus
What is a sequence of nucleotides on a chromosome coding for a particular protein known as?
a gene
Two copies of a gene that come from father and mother are known as?
Alleles
a mutant or alternate allele codes for what?
A faulty protein or no protein at all.
If two alleles are the same they are what?
Homozygous
If two alleles are different they are what?
Heterozygous
What is a recessive disorder?
A disorder where you need two mutant or faulty forms of the allele (homozygous) to exhibit the disorder.
When is a person known as a carrier?
They have one mutant copy and one normal copy of the gene, but don’t have the disease since the normal copy serves the function adequately.
What is a dominant disorder?
One where only one faulty allele (heterozygous) is needed to cause the disorder.
What is an autosomal genetic disorder?
A disorder caused by a faulty gene in an autosome
What are autosomes?
22 of the pairs of chromosomes are autosomes
What happens when a mutant allele is associated with the X-chromosome?
A sex-linked disorder occurs
Why do males have a greater chance of inheriting a sex linked disorder?
Males have only one X chromosome
What are the functions of proteins?
enzymes
cell structure
membrane transport
antibodies
hormones
Why do alternate of mutant alleles cause disorders?
enzymes that don’t work
faulty cell structures
faulty membrane proteins
True or false - all alternate alleles lead to fatal disorders
False
Eye color, hair colour, ABO blood type are examples of what?
Random mutations in alleles.
Alternate alleles can be beneficial how?
Natural selection where organisms with favourable variations win the struggle for survival.
What is cell division?
Production of new cells from pre-existing cells.
What controls cell division?
Cycle control enzymes which, when activated, permit the duplication of nuclear DNA.
How many pairs of chromosomes do humans have?
23 pairs (46 total)
What is cell division useful for?
growth
repair or replacement
What does DNA stand for?
Deoxyribonucleic acid
What has to happen before a cell can divide?
It must replicate the genetic material so that each daughter cell receives identical copies of all genes.
What is DNA packaged as during cell division?
Chromosomes
DNA appears in what shape?
A spiraling double helix
What are the two types of cell division in human cells?
Meiosis and Mitosis
Where does mitosis occur?
in somatic cells (most body cells)
Where does meiosis occur?
in sex cells (cells in ovaries and testes destined to become eggs and sperm)
How may chromosomes does a cell have for meiosis?
23 total
What do sex chromosomes determine?
the sex and the type of gametes they will produce.
What are the sex chromosomes of females?
XX
What are the sex chromosomes of males?
XY
What is cellular respiration?
The process by which glucose is broken down in order to harvest energy to do work in the cell
What is a by-product of cellular respiration?
Heat
What is the opposite reaction to cellular respiration?
Photosynthesis
What is the first step of the process of cellular respiration called? (breakdown of glycose)
Glycolysis
Is glycolysis aerobic or anaerobic?
Anaerobic
What does glycolysis yield?
2 ATP and 2 pyruvic acid per glucose.
The mitochondria convert the pyruvic acid from glycolysis into what?
34 ATP
ATP is produced by catabolic or anabolic reactions?
catabolic
ATP is consumed in what type of reactions?
anabolic
What are the 4 stages of aerobic cellular respiration?
- glycolysis in the cytoplasm, yield 2 pyruvic acid.
- 2 pyruvic acid enter the mitochondria
- Krebs cycle
- electron transport chain (ETC)
How many ATP are produced for every one molecule of glucose consumed in aerobic cellular respiration?
36 ATP
What are the 2 stages of anaerobic respiration?
a. glycolysis in the cytoplasm (yielding 2 pyruvic acid)
b. pyruvic acid fermentation into lactic acid.
Brain and heart muscle and tissue can only use what type of cellular respiration?
aerobic cellular respiration
Cells other than than heart and muscle can use what type of cellular respiration?
aerobic and anaerobic cellular respiration