Unit 1
Characteristics of life & cell basics
Characteristics of life & cell basics
What are the eight characteristics of life?
Organization, Homeostasis, Growth & development, Respond to stimuli, Metabolism, Reproduction, Genetic material, and Evolve
What are the four macromolecules and the elements that comprise them?
Lipids, Carbohydrates, Proteins, and Nucleic Acids
They are made of C, H, O, N, & P
Why do cells have to remain small in size?
To be able to effectively transport materials in and out of the cell.
What organelles are responsible for providing food and energy to cells?
Chloroplast (phototrophs) and the mitochondria (all)
Describe the molecule responsible for carrying genes.
Describe a typical prokaryotic cell.
Small and simple
Lack a nucleus and membrane bund organelles
Circular DNA located in the nuceolus
Describe the linking of monomers into polymers.
In a process called dehydration synthesis water is removed allowing the monomers to bond.
What does cholesterol do to cell membranes?
Cholesterol makes them more rigid or more fluid depending on the concentration present.
Write out the equations for photosynthesis and cellular respiration. Compare and contrast them.
Photosynthesis:
6CO2 + 6H2O + Sun Energy -> C6H12O6 + 6O2
Cellular Respiration:
C6H12O6 + 6O2 -> 6CO2 + 6H2O + ATP Energy
The equations mirror each other with the same molecules on opposing sides
Explain the cell cycle and its phases.
Interphase is broken up into G1 for cell growth, S for DNA replication, and G2 for preparation for cell division. Next is mitosis broken into prophase: the nuclear envelope dissolves and the chromatin condenses into chromosomes. Metaphase: chromosomes line up at the equator. Anaphase: sister chromatids are pulled to opposite poles.Telophase: nuclear envelope reforms, chromosomes uncondense, and the cleavage furrow or cell plate forms. The last step is cytokinesis.
What evidence supports the endosymbiotic theory?
Mitochondria and chloropolast have their own DNA
Mitochondria and chloroplast reproduce similarly to bacteria
Mitochondria and the Chloroplasts have a double membrane
Triglycerides are polymers of what macromolecule that function in what?
Lipids; Long-term energy storage, insulation, and protection
What are the two types of endoplasmic reticulum and what are their unique functions?
The rough, has ribosomes embeded and is close to the nucleus, and the smooth.
The Rough ER helps modify and transport proteins
The Smooth ER helps synthesize and transport lipids and detoxify toxins
What are the steps of cellular respiration and where do they occur?
1. Glycolysis in the cytoplasm
2. Krebs Cycle in the mitochondrial matrix
3. Electron Transport Chain in the inner membrane of the mitochondria
How is DNA replicated?
The enzyme helicase unzips the DNA molecule by breaking hydrogen bonds between bases. DNA Polymerase adds on complementary nucleotides to each old strand. The DNA is completed and retwists into a double helix. This is semiconservative replication.
What characteristic of life can you observe simply by looking at a diagram of a dog.
It is organized
C, H, O
Monosaccharides -> Polysaccharides
Quick energy, cell ID, & cellulose in walls
Ex: Bread, Pasta, Glucose, Fructose, Potato starch
Which way will water move in these scenarios?
1. A cell placed in fresh water
2. A muscle cell in your leg
3. A cell placed in the ocean
1. Water will move into the cell from the hypotonic freshwater
2. Water will move evenly in and out the cell is isotonic
3. Water will move out of the cell into the hypertonic ocean water
What are the steps of photosynthesis (explain) and where do they occur?
1. Light dependant reactions occur in the thylakoid of the chloroplast. Light and water are used to create NADPH and ATP with oxygen as a byproduct
2. Light independant reactions/ Calvin Cycle occur in the stroma of the chloroplast. Carbon dioxide is transformed into glucose with the energy from ATP and NADPH.
Explain how transciption and translation work together.
Transcription takes place in the nucleus where DNA is copied into mRNA by the enzyme RNA polymerase. mRNA leave the nucleus for the ribosome to translate it. The ribosome reads codons and adds the correct amino acid provided by tRNA. After reaching the stop codon UGA a protein is completed.
Cells in both Prokaryotes and Eukaryotes have these features in common
Cell membrane
Genetic material
Cytoplasm
Ribosomes
What are the functions of polypeptides?
Immune response such as antibodies, repair, enzymes, and cell transport
Describe the fluid mosaic model
The cell membrane is composed mainly of phopholipids made up of a hydrophilic polar head and a hydrophobic non-polar tail arranged in a bilayer. There are several embeded proteins used for transport. Cholesterol maintains proper fluidity and carbrohydrates aid in cell labeling and identification.
How do photosynthesis and cellular respiration work together in plants?
Explain in detail!
The cholorplast performs photosynthesis in a two step process that produces glucose. Glucose is then broken down in three steps by cellular respiration at the mitochondria. The end result is 36-38 usable molecules of ATP.
A mutation can lead to cancer. What are the three types of mutations and how will the cancer cells behave?
Substitution, Insertion, and deletion.
The cancer cells can not communicate, perform normal functions, and they steal nutrients from healthy cells by secreting growth hormones.