Organelles and their Functions, Mitosis, Protein Synthesis, and Cell Cycle (Anatomy and Physiology)

Why are cells small?

• to have a bigger SURFACE AREA to VOLUME ratio (SA:V ratio)

—> the smaller the cell the more EFFICIENT it is to exchange nutrients and waste products across the membrane

Cell Theory

1) All living things are made of cells

2) Cells are the basic unit of structure and function in living things

3) New cells are produced from existing cells

Level of Organization of cells (smallest to largest)

Cells —> Tissues—> Organs—> Organ system —> Organism

Microfilaments 

made up of threadlike structure called ACTIN ( a type of protein) to help provide structure

Microtubules

hollow structures made up of TUBULINS which help extend the cell by working with centrioles when the cell is ready to replicate itself 

________ is an example of a structure containing actin.

Skeletal muscle cells

Cytoskeleton

network of protein filaments that give cell structure and shape

4 Common Examples of Cytoskeleton

Microvilli, Centrioles, Cilia, Flagella

Microvilli

fingerlike extensions that help increase surface area

Centrioles

Cylindrical structures that direct chromosomes during mitosis

Cilia

Long, slender extensions of plasma membrane that can move independently 

Flagella

Very long extensions of plasma membrane that can move independently

4 Main Structures Involved in Protein Synthesis 

Ribosomes, Golgi Apparatus, Rough E.R, and Smooth E.R

Ribosomes

tiny particles made of RNA that help build protein

Rough Endoplasmic Reticulum

Network of membranes covered in ribosomes

• known as PROTEIN FACTORY 

Smooth Endoplasmic Reticulum

Membranes with no ribosomes that build lipids and carbohydrates

Golgi Appartus

Flattened discs of membrane that package proteins in vesicles

Secretory Vesicles

contain material to be released outside of the cell through exocytosis

Lysosomes

digestive enzymes that break down worn cell parts, bacteria, or viruses

Perioxisomes

smaller than lysosomes and help digest FATTY ACIDS and AMINO ACIDS 

Mitosis is used for ________, ___________, and _____________.

healing, growth, replenishment

• “Heather grows relishes” 

The Cell Cycle Stages

G1, S, G2, M

• Cytokinesis is technically when the cycle repeats and the cytoplasm divides 

G1

growth, metabolizing, promotes homeostasis

• there is a G1 check point where DNA is assessed

S

Synthesis, where the DNA is replicated and the chromosomes are replicated

G2

Continued growth of the cell

• G2 is the checkpoint that assesses overall health of the cell

M 

Mitosis, meaning a new body/somatic cells is created 

If the cell does not pass any of the G1 or G2 checkpoints then the _________ ____!

lysosomes POP

Mitosis

the process of cell division in eukaryotic cells

The 4 stages of Eukaryotic cell division 

Prophase, Metaphase, Anaphase, and Telophase 

Mitosis only occurs in ________ cells

somatic (human)

Apoptosis

where the lysosomes are ruptured

• part of membrane breaks off

• neighboring cells clean up remains 

Prophase

chromosomes in the NUCLEUS are beginning to untangle

Metaphase

• “M” for middle

• the chromosomes line in the middle 

• nucleus gets ready to break down for cell division

Anaphase 

The spindle fibers pull SISTER CHROMATIDS APART/AWAY

Telophase

chromosomes move to opposite sides of the cell where new nuclei form around each set of chromosomes and prepares to divide

Cytokensis

the final divides the cytoplasm into two daughters cells or DIPLOIDS

Interphase is apart of ___________, where DNA is still loose and stringy in the nucleus.

Prophase