Biology:Cells

The cell is the basic unit of life. Cells contribute to the organization of life and provide the environment in which organelles function. Not all cells are the same.Briefly describe how the function of the organelles within a cell determines the function of that cell.

Some cells which have certain organelles will do specific tasks. For example, white blood cells have more ribosomes which are used to fight diseases. Sperm cells have flagella, which facilitate travel.

Structure and function: Ribosomes

These are complexes that make up proteins, carrying out protein synthesis. It is made up of ribosomal RNA and protein. Free ribosomes are found floating in the cytoplasm, while bound ribosomes are found attached to the rough ER

Structure and function: Endoplasmic Reticulum

Rough: Membranous sacs which produces proteins Smooth:synthesizes lipids, detoxifies poison, assists in digestive process of cells.

Structure and function: Golgi Complex

Proteins are modified and stored, then sent out to different locations in the cell. It is made up of flattened membranous sacs called cisternae.

Structure and function: Mitochondria

This organelle includes ATP to use as energy. It is the sight of cellular respiration, which is where oxygen is used to make atp by extracting energy from sugars, fats, and other fuels.

Structure and function: Lysosomes

Are involved in the break down of cells, contains digestive enzymes.

Structure and function: Vacuoles

this organelle is involved in cell growth, by absorbing water, it contains most of the cells inorganic ions.

Structure and function: Chloroplasts

This organelle is involved in photosynthesis. It contains many folds in it's inner membrane to reach more sunlight.

Explain how the double membrane within Mitochondria and Chloroplasts help with their functions of metabolic reactions (cellular respiration, and photosynthesis). Include why increased surface area is important within both organelles.

The double membrane increases the surface area of the organelles. The surface of the organelles is where many reactions occur, such as the creation of ATP. The larger the surface area, the more protein the mitochondria will receive, which will lead to more ATP produced. The larger the surface area, the more sunlight chloroplast will absorb, leading to more sucrose being produced.

Compare the surface area to volume of a cell. What happens to volume when surface area increases?

As a cell gets bigger, the volume of the cell will increase faster than the surface area. The demand for more needs in the inside will be larger than the outside of the cell. (larger than what the cell can intake/hold)

What can cells do to help increase surface area and/or decrease volume?

Folds can help increase the surface area or decrease volume. (so can the growth of filia (long thin hairs) which stretch out to gain more surface area.

Hydrophilic heads: Explain the orientation of the heads in relation to the plasma membrane.

The hydrophilic head will face the outside of the membrane to where the water is.

Hydrophobic Fatty acid tails: Explain the orientation of the tails in relationship to the plasma membrane.

The tails are hydrophobic, meaning they will stay close together to avoid the water/fluid surrounding the outside of the membrane. This is what helps maintain the membrane, by monitoring what comes in and out of the cell. The hydrophobic tails face each other, their heads on the outside.

Role: phospholipids

They build up the membrane of a cell. They also monitor the transport and excretion of cell matter.

Role: Protein

They scatter throughout phospholipids in the membrane, assisting in passive and active transport. (used in transport of the needs of a cell)

Role: Cholesterol

They help maintain the fluidity of the membrane

Role: Glycoprotein

Used in Cell recognition

Role: Glycolipid

Used in cell recognition

Explain why the plasma membrane is considered semi-permeable.

Some things make it through and some things can't.

Explain how the structure of a molecule affects its ability to pass through the plasma membrane.

The size and whether it is polar/nonpolar. Also, the fact that some molecules get picked up by proteins also determines their ability to pass.

How does Polarity play a role in movement of molecules through the membrane?

The smaller, nonpolar molecules will pass more frequently due to them being passive transport.

Cell walls also have permeability, what are some differences in cell wall composition from Plants, Prokaryotes, and Fungi?

Plants have cellulose, prokaryotes have petidoglycon, fungi have chitin.

Identify the two types of passive transport and state which part of the plasma membrane is used for each type of transport.

Osmosis and diffusion. The nutrients goes straight through the phospholipids in the membrane.

Describe the type of molecules that are able to pass through the cell membrane by simple diffusion and give examples.

Small, nonpolar molecules. N2, O2, CO2

Describe the type of molecules that are able to pass through the cell membrane by facilitated diffusion and give examples.

Polar molecules and ions. Carbohydrates, amino acids, ions.

Describe how aquaporins work to allow for water movement through cell walls.

They open up a channel that allows for simple diffusion to go across

Membranes and membrane-bound organelles in eukaryotic cells compartmentalize intracellular metabolic processes and specific enzymatic reactions. Identify the organelles that compartmentalize intracellular metabolic processes and state the processes that are occuring.

Ribosomes, lysosomes, vacuole, ER, Golgi apparatus, Nucleus, mitochondria, chloroplast.

Identify two organelles that contain internal membranes and state the process that occur in each organelle.

Mitochondria and Chloroplasts. Mitochondria does electron change and chloroplasts do photosynthesis.

Explain how the folding of the internal membrane is beneficial to carrying out the process.

Provides more surface area to get more resources

Describe the involvement of the membrane in the cellular processes.

Monitors what enters and what exits the cell

Describe the similarities and differences and compartmentalization between prokaryotic and eukaryotic cells.

Prokaryotes have a nucleoid region, eukaryotics have a membrane. Both have ribosomes.

Describe the endosymbiotic theory.

This theory involves mitochondria and it's origin. It seems to have been an independent prokaryote before being consumed by a eukaryotic cell. (Phagocytosis)

Describe two pieces of evidence that support the endosymbiotic theory

- They have their own DNA - Have they're own ribosomes - the only 2 organelles with a double membrane