Biology Review Ch 5 - 6

Review

Chapters

5 & 6

Chapter 5 Photosythesis and Cellular Respiration

Energy and Living Things:

Energy from sunlight flows through living systems, from autotrophs to heterotrophs

Photosynthesis and cellular respiration form a cycle because one process uses the products of the other

ATP supplies cells with energy needed for metabolism

Photosynthesis

Photosynthesis has three stages. First, energy is captured from sunlight. Second, energy is temporarily stored in ATP and NADPH. Third, organic compounds are made using ATP, NADPH, and carbon dioxide.

Pigments absorb light energy during photosynthesis

Electrons excited by light, travel through the electron transport chains in which ATP and NADPH are produced

Photosynthesis

Through carbon dioxide fixation, by the Calvin Cycle, carbon dioxide in the atmosphere is used to make organic compounds, which store energy.

Photosynthesis is directly affected by environmental factors such as the intensity of light, the concentration of carbon dioxide, and temperature.

Cellular Respiration

Cellular respiration has two stages: First, glucose is broken down to pyruvate during glycolsis, making

some ATP. Second, a large amount of ATP is made during aerobic respiration.

When oxygen is not present, NAD+ is recycled during the anaerobic process of fermentation.

The Krebs Cycle is a series of reactions that produce energy storing molecules during aerobic respiration.

Cellular Respiration

During aerobic respiration, large amounts of ATP are made in an electron transport chain.

When oxygen is not present, fermentation follows glycolysis, regenerating NAD+ needed for glycolysis to continue.

Chapter 6 Chromosomes and Cell Reproduction

Chromosomes:

Cell division allows organisms to reproduce asexually, grow, replace worn-out or damaged tissues, and form gametes

Bacteria reproduce by binary fission

Before cell division, DNA coils around proteins and the chromosomes condense. At cell division, each chromosome consists of two chromatids attached at the centromere.

Chapter 6 Chromosomes and Cell Reproduction

Each organism has a characteristic number of chromosomes

Human somatic cells are diploid, with 23 pairs of homologous chromosomes.

Human gamates are haploid, with 23 chromosomes.

Sex chromosomes carry information that determines an organism’s sex or gender

Changes in chromosome number or structure can cause abnormal development.

Karotypes are used to examine an individual’s chromosomes.

The Cell Cycle The life of a eukaryotic cell, known as the cell cycle,

includes interphase, mytosis, and cytokinesis.

Interphase consist of three phases Growth DNA synthesis (replication) Preparation for cell division

A cell about to divide enters the mitosis and cytokinesis phases of the cell cycle

The Cell Cycle is carefully controlled; failure of this control can result in cancer

Mitosis and Cykokinesis During mitosis, spindle fibers drag the chromatids to

opposite poles of the cell.

A nuclear envelope forms.

Each resulting nucleus contains a copy of the original cell’s chromosomes.

Cytokinesis in animal cells occurs when a belt of protein threads pinches the cell member in half, splitting the cell into two separate cells.

Cytokinesis in plant cells occurs when vesicles from the Golgi Apparatus fuse to form a plate.