Ib Biology Sl Topic 2 Revision Notes

3. Identify the 3 domains of living things. Which domains include one-celled organisms with no nucleus?

Without the cells there will be no life. A cell is the the building block of the body. There 2 different types of cells there are animal cell and plants cells. Eukaryote is any cell that has a cell membrane bound. It also contains organelles.

According to Mattias Schleiden and Theodor Schwann the cell is the basic unit of life(Cell Theory- OI). Two common types of cells are the plant and animal cells. Although both kinds of cells share many similar, abundant structures, they also have varying descrepancies from cell to cell. Without a doubt, the nucleus is the most important organelle in the plant cell, even though, the lysosome is the most important structure in the animal cell.

2) The mRNA exits through the pores in the nuclear envelope and travels to the cytoplasm, where it then binds to ribosomes.

-Sarcoplasmic Reticulum (SR) then releases Calcium which binds to troponin in the thin filament, exposing myosin-binding sites;

* Cells allow things to go in and out of the organism (allows diffusion to happen so good things go in and bad things go out)

The virus fuses with the cell’s plasma membrane. The capsid proteins are removed, releasing the viral proteins and RNA. Reverse transcriptase catalyzes the synthesis of a DNA strand complementary to the viral RNA. Reverse transcriptase catalyzes the synthesis of a second DNA strand complementary to the first. The double-stranded DNA is incorporated as a provirus into the cell’s DNA. Proviral genes are transcribed into RNA molecules, which serve as genomes for the next viral generation and as mRNAs for translation into viral proteins. The viral proteins include capsid proteins and reverse transcriptase (made in the cytosol) and envelope glycoproteins (made in the ER). Vesicles transport the glycoproteins from the ER to the cell’s plasma membrane. Capsids are assembled around viral genomes and reverse transcriptase molecules. New viruses bud off from the host cell.

Cell: In biology, the smallest unit that can perform all life processes; cells are covered by a membrane and contain DNA and cytoplasm.

Cells are the basic units of structure and function in an organism, and Cells come only from the reproduction of existing cells.

Coelomates have an enclosed body cavity, which means advance muscle structure, enhanced locomotor capabilities, and more structural integrity.

B. Growth – over a lifetime, organisms grow larger through an increase in size or number of cells. Differentiation is when cells have specialized functions

instructions from DNA. Proteins from the cytoplasm enter the the nucleus through the nuclear pores and combine with rRNA to make subunits of ribosomes. The small and large subunits of ribosomes then exit the nucleus also through the nuclear pores and then join in the cytoplasm to make a ribosome. Ribosomes are either bound or free in the cytoplasm. Free ribosomes in the cytoplasm make proteins that function in the cytoplasm. Bound ribosomes are bound to the nuclear envelope or the rough endoplasmic reticulum, where they make proteins that are later packaged into vesicles . The endoplasmic reticulum is made up of cisternae, cisternae consists of connected flattened sacs and tubules. The inside of the endoplasmic reticulum is called the endoplasmic

The cell is the smallest unit able to sustain life, and they are often referred to as the building blocks of life. There are two primary types of cell, which are categorized according to the way their genetic material is packaged, rather than size or shape. These are:

hydrogen ions are moved into the thylakoid space by action of electron carriers; higher concentration of / more, hydrogen ions / protons reduces the pH; R hydrogen, H A hydrogen ions produced in lumen hydrogen ions, move / diffuse, down concentration gradient ; across / through, (thylakoid) membrane / from lumen to stroma; through ATP synthetase / synthase / protein channel / stalked particles; generates ATP; AVP; e.g. ref. to by chemiosmosis ref. to an electrochemical gradient / proton motive force max 4

In particular, cargoes and v-SNARE are sorted into newly-forming buds with the assistance of cargo receptors, coat proteins and some other factors. Vesicle movement is mediated by motor proteins along with cytoskeletons elements which refer to actin filaments or microtubule in most cases. Upon vesicles arrival to the vicinity of target membrane, tethering proteins initiate the first physical contact between vesicles and the target membrane. Finally, the fusion of vesicular and target membrane is mediated by the interaction of v-SNARE on vesicles and t-SNARE on target compartment.