MBB 231 Lec 1 - Basics

The three tenants of cell theory?

1) All organisms are made of one or more cells

2) The cell is the structural unit of life

3) Cells only arise by division from a pre-existing cell

What are the 10 basic properties of cells?

1) Life - most basic property of cells

2) Cells are complex and organized

3) Cells have a genetic program and the means to use it

4) Cells can make more of themselves thru mitosis and meiosis

5) Cells gain and use energy thru photosynthesis and respiration

6) Cells carry out a variety of chemical rxns

7) Cells are involved in mechanical activities

8) Cells can respond to stimuli (w/ receptors to initiate responses)

9) Cells can self-regulate

10) Cells evolve

How is genetic material (information) stored and used in a cell?

• Info gets packed into a set of chromosomes

• genes store info and constitute blueprints for all activities

  • such as: cellular structures, activities, division

• All cells in an organism have identical copies of DNA

• Genes can mutate (change genetic information)

  • forms the basis of evolution.

What’s the difference between mitosis and meiosis?

Mitosis: Single parent divides two identical daughter cells

• For non-sex cells

Meiosis: sex-cell division where 1 parent splits into 4 different gamete cells (sperm and egg) which have half the chromosomes from the parent

How do cells GAIN energy?

Photosynthesis —> sunlight provides fuel for organisms

• Animal cells turn photosynthetic products into glucose

Cellular Respiration —> turns glucose into ATP (energy)

What is the cell’s metabolism?

the sum total of chemical reactions in a cell

Summarize how metabolism works in a cell?

• Cells function like mini chemical plants

• Enzymes help with chemical changes to increase rxn rates

• All of the reactions combined is the cell’s metabolism

What are mechanical activities of a cell?

Transport materials, make and break structures, move onto different sites

• Motor proteins help with activity via initializing mechanical changes within the cell

How do cells receive stimuli? How do they respond to stimuli?

Using receptors that signaling molecules in their environment

• Signaling molecules include: hormones, growth factors, extracellular materials, substances from other cells

They respond by altering metabolism, moving from place to place, altering gene expression, or kms

What is self regulation in cells? How do they do it?

To keep the cell in it’s appropriate state —> theyre protected from flux in composition and behaviour

• They have feedback circuits to return it to its OG state

  • this is encoded into their genetic info

  • Cellular factors in genetic info help make this spontaneous

What is LUCA

last universal common ancestor

What are 3 things common between prokaryotes and eukaryotes

1) identical genetic language

2) common set of metabolic pathways

3) share many common structural features

What are things eukaryotes have that prokaryotes dont?

• nucleus with complex chromosomes

• membrane-bound organelles

• complex cytoskeletal filaments and motor proteins

• complex cilia and flagella

• mitosis stage has mitotic spindle for chromosome segregation

• sexual reproduction using meiosis

• Complex organization (general)

  • Temporal and spatial arrangements of biochemical events for cellular function

  • uses lots of energy to maintain membrane bound domains in biochemical events

What are ideal advantages for studying model organisms? (to study human cells)

1) Simple organism

2) Fast generating

3) Generate lots of offspring

4) Genetic info is easy to manipulate in lab

5) Cheap to breed and treat

6) Have many genes that are conserved with humans (genes evolutionary derived close to our generation)

match the following common names with their species names

What are three things that limit the size of a cell?

1) The need to keep adequate local concentrations of substances needed for cell functions (e.g., mRNA, ribosomes, etc)

2) The need adequate SA-Vol ratio

3) The rates which molecules can diffuse

What is the importance of a cells surface area to volume ratio? What if the cell’s volume was too large relative to its surface area?

High SA needed to exchange materials (i.e., oxygen) btwn the cell’s surface its surroundings

Cell volume determines the amount of exchange needed (if its big, it needs a lot)

If SA not enough to acomodate exchange for cell’s volume: cell wouldnt have enough nutrients and release enough wastes

How do molecules move within the cytosol? (I.e., transport between cell membrane) (theres only 2)

1) Diffusion (unassisted motion)

2) Active transport (Specialized machinery to help with movement)

(Skippable?) Define Virus, Provirus, Virion, Viroid, and prion

• Virus = infectious agent that replicates inside a living cell

• Provirus = Virus genome that’s incorporated into the genome of its host

• Virion = a complete viral particle (has a genome, capsid, sometimes envelope)

• Viroid = Infectious agent made of mainly RNA (no coat proteins)

• Prion = infectious protein that transmits its folded shape to other native folded proteins

What is the family name of this virus?

corona

What is the scientific method?

The formation of a hypothesis where data is collected and interpreted from tests. These results are used to accept or reject the hypothesis.

What is a hypothesis?

A statement consistent with most of the data which can also be a model —> MUST be testable

What is a theory?

A hypothesis that has been tested by investigator using different approaches; it is widely accepted (e.g., cell theory, theory of evolution)

What is a law?

Theory that is tested and confirmed over a long time period without doubt (E.g., newton’s law of motion)

(Skippable?) What are 7 things part of a peer-reviewed scientific journal?

1) Abstract

2) Introduction

3) Methods

4) Results

5) Figures

6) Discussion

7) References