Topic 1: Cell Biology

What are the 7 functions of life? (MRS H GEN)

Growth, homeostasis, nutrition, excretion, stimuli, reproduction, metabolism

What are the 3 cell theory principles?

1. Living organisms are made of cells

2. Cells are the smallest unit of life

3. All cells come from pre-existing cells

Organisms that need to consume other plants/animals for nutrients

Heterotrophs

Organisms that can make their own food through chemical reactions

Autotrophs

What is the surface area of a cell?

Cell membrane

What is the volume of a cell?

Organelles

What is the relationship between surface area and volume increasing?

Volume increases faster than surface area

Are paramecium heterotrophs or autotrophs?

Heterotrophs

Are chlamydamonus heterotrophs or autotrophs?

Autotrophs

A constant internal environment is maintained by collecting excess water in the contractile vacuoles and then expelling it through the plasma membrane

Osmoregulation

Unspecialised cells developing into cells with a distinct structure and function

Differentiation

Properties that exist due to multiple systems/components of the body working together (cookie recipe!!)

Emergent properties

How is stem-cell therapy used to treat Stargardt's disease?

Retinal cells (derived from human embryonic cells) are injected into the eye to regenerate the photoreceptor cells

How is stem-cell therapy used to treat Leukemia?

Multipotent stem cells (called HSCs) are harvested from bone marrow or umbilical cord blood and injected back into the body to generate new, healthy white blood cells

Which are more complex: eukaryotes or prokaryotes?

Eukaryotes

What are the 2 things that separates eukaryotes and prokaryotes?

1. DNA in prokaryotes is freely floating

2. Prokaryotic cells do not have membrane-bound organelles

Are plant cells prokaryotic or eukaryotic?

Eukaryotic

What is binary fission?

Separation of the parent cell into two identical daughter cells

Part of the nucleus which is involved in the production of ribosomes.

Nucleolus

Process in which substances are brought into the cell via budding

Endocytosis

Process in which substances are excreted from cell via secretory vesicles

Exocytosis

What is an amphipathic molecule? (ex. phospholipid bilayer)

Hydrophobic and hydrophilic

Channel protein

Allows passive transport in and out of the cell

Carrier protein

Proteins bind to substances on one side of the membrane, then change shape to transport them to the other side (aka: protein pump)

Recognition protein

Deciding between self and non-self cells, allows self inside cell

Receptor protein

Relay information from the inside or outside of the cell

Enzyme protein

Enhance the rate of reactions that happen at the membrane level

Davson-Danielli model

Argued that there was a full exterior layer of proteins

Does diffusion happen faster at higher or lower temperatures?

Higher

What is diffusion?

The movement of particles from a region of high concentration to a region of low concentration, and is the result of the random motion of particles

What are the concentration gradients for osmosis and diffusion?

Osmosis: low to high

Diffusion: high to low

Why do organs need to be kept in an isotonic, saline solution?

To ensure osmolarity of the solution is the isotonic to cytoplasm of cells in organ

What did the Miller-Urey prove?

Non-living synthesis of simple organic molecules was possible

Define a nucleosome

The section of DNA wrapped around histones

How do you find the mitotic index?

P+M+A+T/total cells

What is the relationship between smoking and cancer?

The likelihood of getting cancer from smoking increases with age