Biology Study Notes
1. The Big Idea of Biology
Biology is the study of life and the systems that keep organisms alive.
Everything else in the subject connects back to these three questions:
1. How do living things build themselves? (cells, DNA, proteins)
2. How do living things stay alive? (energy, homeostasis)
3. How do living things grow and change over time? (genetics, evolution)
If you remember that, the units make way more sense.
2. The Cell — The Basic Unit of Life
Two types of cells
Prokaryotes → simple, no nucleus (bacteria)
Eukaryotes → complex, have a nucleus (plants, animals, fungi)
Cell organelles (what they do)
Nucleus – stores DNA, “control center”
Mitochondria – makes ATP energy, “powerhouse”
Ribosomes – build proteins
Endoplasmic Reticulum (ER)
Smooth: lipids
Rough: proteins
Golgi body – packages and ships molecules
Cell membrane – controls what enters/exits
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, Chloroplasts (plants only) – photosynthesis
Cell wall – structure/support in plants & some bacteria
Cell membrane transport
Diffusion – molecules spread out naturally
Osmosis – diffusion of water
Active transport – uses energy to move things against a gradient
3. Photosynthesis vs. Cellular Respiration
Photosynthesis (plants)
Plants turn sunlight → glucose.
Formula:
\text{CO}_2 + \text{H}_2\text{O} + \text{sunlight} \rightarrow
\text{C}_6\text{H}_{12}\text{O}_6 + \text{O}_2
Happens in: chloroplasts
Cellular Respiration (all organisms)
Cells break down glucose → ATP energy.
Formula:
\text{C}_6\text{H}_{12}\text{O}_6 + \text{O}_2 \rightarrow \text{ATP} + \text{CO}_2
+ \text{H}_2\text{O}
Happens in: mitochondria
Opposites:
Plants make sugar → animals use it
Plants make oxygen → animals use it
4. DNA & Genetics
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1. The Big Idea of Biology
Biology is the study of life and the systems that keep organisms alive.
Everything else in the subject connects back to these three questions:
1. How do living things build themselves? (cells, DNA, proteins)
2. How do living things stay alive? (energy, homeostasis)
3. How do living things grow and change over time? (genetics, evolution)
If you remember that, the units make way more sense.
2. The Cell — The Basic Unit of Life
Two types of cells
Prokaryotes → simple, no nucleus (bacteria)
Eukaryotes → complex, have a nucleus (plants, animals, fungi)
Cell organelles (what they do)
Nucleus – stores DNA, “control center”
Mitochondria – makes ATP energy, “powerhouse”
Ribosomes – build proteins
Endoplasmic Reticulum (ER)
Smooth: lipids
Rough: proteins
Golgi body – packages and ships molecules
Cell membrane – controls what enters/exits
Untitled 1
, Chloroplasts (plants only) – photosynthesis
Cell wall – structure/support in plants & some bacteria
Cell membrane transport
Diffusion – molecules spread out naturally
Osmosis – diffusion of water
Active transport – uses energy to move things against a gradient
3. Photosynthesis vs. Cellular Respiration
Photosynthesis (plants)
Plants turn sunlight → glucose.
Formula:
\text{CO}_2 + \text{H}_2\text{O} + \text{sunlight} \rightarrow
\text{C}_6\text{H}_{12}\text{O}_6 + \text{O}_2
Happens in: chloroplasts
Cellular Respiration (all organisms)
Cells break down glucose → ATP energy.
Formula:
\text{C}_6\text{H}_{12}\text{O}_6 + \text{O}_2 \rightarrow \text{ATP} + \text{CO}_2
+ \text{H}_2\text{O}
Happens in: mitochondria
Opposites:
Plants make sugar → animals use it
Plants make oxygen → animals use it
4. DNA & Genetics
Untitled 2
