Biology Exam 3 - Cellular energy and reproduction

freshman year semester 2

Why is regulation of cell reproduction necessary?

A lack of regulation can cause cancer or genetic disorders

What does the G1 checkpoint look for?

Checks cell growth

What does the G2 checkpoint look for?

Checks DNA synthesis

What does the M checkpoint look for?

Checks for correct number of chromosomes

Describe the M checkpoint

During Mitosis, during Metaphase

Proto-oncogenes

Gene that regulates cell cycle; stop signal

Tumor suppressor genes

Gene that regulates cell cycle; go signal

Interphase

Clearly visible nucleus, chromosomes are not visible, DNA still there (chromatins), 2 pairs of centrioles

Prophase

Nuclear envelope begins to disintegrate, nucleolus no longer visible, chromosomes become more distinct, centrioles migrate to poles (ends) of the cell, spindle fibers form from centrioles

Prometaphase

Aster fibers that anchor centrioles to the inside of the cell membrane, Chromosomes are clearly distinct, spindle fibers stretch towards center of cell

Metaphase

Chromosomes align along the midplate/center of the cell, aka the “equatorial plane,” and the spindle fibers connect to the chromosomes from both sides

Anaphase

Spindle fibers pull the sister chromatids away from each other, towards the poles

Telophase

Spindle fibers disappear, nuclear envelope begins to reform, cleavage furrow pushes membrane inward

Cytokinesis

Two daughter cells created, cell cycle begins anew

Genome

Traits, DNA, chromosomes; all the DNA in a cell

DNA

Deoxyribonucleic acid; composed of many nucleotides; found in cell nucleus

DNA structure

Double helix

Chromatin

Tangled molecules of DNA

Chromosomes

2 molecules, 2 copies of same DNA, composed of 2 sister chromatids; different genes in each section of the molecule

Somatic cells

“Body cells”: bone, muscle, blood, organ, skin, etc

Germ cells

“Gametes” or “Sex cells”: sprm cells, egg cells

Homologous Chromosomes

Pair of maternal and paternal chromosomes; human somatic cells have 23 pairs of them; TOTAL OF 46

Diploid

“2n”: 46 chromosomes

Haploid

“n” 23 chromosomes; characteristic of human gametes/sex cells

Zygote

Fertilized egg

Embryo

Results from zygote multiplying

G1 phase

Interphase; cell growth and metabolism, cell performing its function

S phase “synthesis phase”

Interphase; DNA synthesis

G2 phase

Interphase; cell prepares for “M phase” (mitosis and cytokinesis)

Why mitosis occurs

Growth, maintaining healthy tissues, replace old/damaged cells

G0 phase

Some cells do not have M phase, such as nerve cells and muscle cells

Aerobic cellular respiration

Glucose + Oxygen = Carbon dioxide, water, energy

Photosynthesis

Carbon dioxide + water + solar energy = Glucose and Oxygen

Chloroplast

Found in plants and algae, allows photosynthesis to occur

Thylakoid

Contains chlorophyll, a photosynthetic pigment

Granum

Stack of thylakoid

Stroma

Empty space in chloroplast

Light dependent reactions

Photosynthesis PHASE 1: creates oxygen from water molecules, uses thylakoids

Light-independent (dark) reactions

Photosynthesis PHASE 2: Uses CO2 and the Calvin Cycle to create glucose (C6H12O)

Glycolysis

Aerobic Cellular Respiration PHASE 1: Takes place in cytosol, generates 2 ATP; Glucose —> 2 Pyruvate + 2 ATP

Formation of acetyl-CoA

Aerobic Cellular Respiration PHASE 2: Takes place in mitochondria, no ATP, intermediate

Citric Acid cycle

Aerobic Cellular Respiration PHASE 3: Takes place in mitochondria, 2 ATP generated

Oxidative Phosphorylation

Aerobic Cellular Respiration PHASE 4: Takes place in mitochrondria, 32-34 ATP generated

Anaerobic Cellular Respiration

ABSENCE of oxygen; lactic acid fermentation, alcohol fermentation

Lactic Acid

Fermentation taking place in human muscle cells

Alcohol

Fermentation takes place in yeast